Yoma 20b ~ From The Talmudology Yom Kippur Archives: Sound Propagation at Night

Tomorrow evening (or in a few hours if you are in Australia) we observe Yom Kippur, the Day of Atonement. So we will reach into the Talmudology archives to a post that discussed the propagation of sound at night.

In discussing the service on Yom Kippur, the holiest day of the Jewish Year, the Talmud notes that the voice of the Cohen Gadol, the High Priest, could be heard from a distance of ten parsangs. In case you were wondering, a parsang is an old Persian measure, and is about 3 miles or almost 5km. This means that the voice of the High Priest could be heard over 30 miles away! The Talmud notes that it could be heard at this distance even during the day, when sound does not travel as far as it does at night. Here it is, in the original:

שקלים כ,א

דְּאָמַר מָר: וּכְבָר אָמַר ״אָנָא הַשֵּׁם״ וְנִשְׁמַע קוֹלוֹ בִּירִיחוֹ. וְאָמַר רַבָּה בַּר בַּר חָנָה אָמַר רַבִּי יוֹחָנָן: מִירוּשָׁלַיִם לִירִיחוֹ עֲשַׂר פַּרְסֵי

וְאַף עַל גַּב דְּהָכָא אִיכָּא חוּלְשָׁא, וְהָכָא לֵיכָּא חוּלְשָׁא. וְהָכָא יְמָמָא, וְהָתָם לֵילְיָא

דְּאָמַר רַבִּי לֵוִי: מִפְּנֵי מָה אֵין קוֹלוֹ שֶׁל אָדָם נִשְׁמָע בַּיּוֹם כְּדֶרֶךְ שֶׁנִּשְׁמָע בַּלַּיְלָה? מִפְּנֵי גַּלְגַּל חַמָּה שֶׁמְּנַסֵּר בָּרָקִיעַ כְּחָרָשׁ הַמְנַסֵּר בַּאֲרָזִים

There already was an incident where the High Priest recited, in his confession that accompanied the placing of hands on his bull on Yom Kippur: Please God, and his voice was heard in Jericho. And Rabba bar bar Chana said that Rabbi Yochanan said: The distance from Jerusalem to Jericho is ten parasangs.

…here it was during the day, when sound does not travel as well, that the High Priest recited his confession… As Rabbi Levi said: Why is a person’s voice not heard during the day in the manner that it is during the night? It is due to the fact that the sound of the sphere of the sun traversing the sky generates noise like the noise generated by a carpenter sawing cedars, and that noise drowns out other sounds…

As we approach Yom Kippur, we might ask if this is true? Does sound really travel further at night? And if so, why?

Yes. It is true

Rabbi Levi is correct. Sound does indeed travel further at night, as you can see below in this helpful graphic. (For the man with the trumpet, think Cohen Gadol. For the dog, think Jericho.)

From here.

The first thing to know is that the speed of sound is dependent on the temperature of the air. Sound moves quicker in warm air and slower in cold air. During the day the sun heats up the earth’s surface, and in particular it heats up the air that is closest to the ground, which is where the sound travels the fastest. But a heat gradient bends the sound waves upwards, much in the same way that a lens bends light rays. (The gradient in which atmospheric temperature decreases with elevation by an amount known as the adiabatic lapse rate.) As a result, the sound waves travels up and away from the listener, and the sounds are quieter.

The reverse happens at night. At night the ground cools quickly. The higher air is warmer than the air close to the ground. The sound further from the ground travels faster at night causing the sound wave to refract back towards the earth. The listener now hears them as louder than they were during the day. It’s physics! (Though it should be noted that some physicists dispute this explanation.)

It’s not just sound waves

Why radio waves travel further at night. From here.

Here’s a fact that Rabbi Levi did not know. It’s not just sound that is heard better at night. Radio waves are heard better at night too, though for an entirely different reason. To be precise, this does not happen with all radio waves, but just those on the AM and short wave frequencies. Because radio waves only travel in straight lines, they do not follow the curvature of the earth’s surface, and so have a natural range of only 30-40 miles. But they can be transmitted up to the ionosphere, where they bounce off of it and down, back to earth. At night, that ionosphere is protected from the electromagnetic radiation that streams from the sun and tends to distort it. And so the radio waves are reflected back down with less interference, which means they travel further and are easier to detect. As a result, some distant AM radio stations (remember those?) can only be heard at night, though the whole thing becomes rather a moot point since nearly everything broadcast can now be found on the internet, for which the ionosphere is not needed.

Noise pollution

We have demonstrated that sound travels further at night, using our knowledge of the properties of sound waves and the phenomenon of refraction. Rabbi Levi knew none of this, but he had something that very few of us today have: a quiet natural environment. What many of us never experience thanks to noise pollution, he experienced each and every night. He, together with the other sages of the Talmud lived in a world that had no noise other than the sound of human voices around a crackling fire and the background music of the natural world. It was an utterly different experience. Our modern world has given us many things to be grateful for, but noise is not one of them.

May you be blessed for a quiet and peaceful year ahead.

גמר טוב

{Want more Talmudology about Yom Kippur? Click here and here.]

Bava Basra 97b ~ Wine and Snake Venom

In today’s page of Talmud there is brief reference to uncovered wine that is left overnight.  This wine should not be drunk because "סכנה היא" – it is dangerous to do so. Shmuel ben Meir, known as the Rashbam (d. ~1158) outlines the cause of this danger: ואיכא למיחש שמא שתה הימנו נחש - "we should be concerned that a snake may have drank from the wine."  The Rashbam, usually known for his lengthy commentaries, left out the most important part of the explanation. While drinking from the water, perhaps the snake expelled some of its venom into the wine, which would then become dangerous to drink.

Don't touch that wine

The rabbis of the Talmud were very worried indeed about the health effects of water - and wine - that had been left uncovered.  This concern was codified by Maimonides, and later by Ya'akov ben Asher (d. 1340) in his famous halakhic work called the Arba'ah Turim. 

טור יורה דעה הלכות מאכלי עובדי כוכבים סימן קטז 

דברים האסורים משום סכנה
  יש דברים שאסרום חכמים משום סכנה כגון משקין שנתגלו שיש לחוש שמא שתה מהן נחש והטיל בהן ארס אפי' אם שתו מהן אחרים ולא הוזקו אין לשתות מהן  שיש נחש שהארס צף למעלה ויש שארס שלו מפעפע עד אמצעית המשקה  ויש שהארס שלו שוקע לשולי הכלי לפיכך אפי' שתו ממנו אחרים ולא הוזקו אין לשתות מהן דשמא ארס של הנחש ששתה מהן שוקע ואלו המשקין שיש בהן משום גילוי מים יין חלב ודבש ושום כתוש 

Tur, Yoreh De'ah 116. Things that are Prohibited Because they are Dangerous

There are things that the rabbis of the Talmud prohibited because they are dangerous. For example, liquids that were left uncovered, because of the possibility that a snake drank from the water and expelled some of its poison into them. Even if others had drunk from the liquid, and not been injured, one should not drink from them.  For some snake venom floats on the surface, and some sinks to the middle and some moves to the edges of the vessel. Therefore, even if others had drunk and had suffered no harm, one should not drink from them, for perhaps the venom from the snake that had drunk the water had sunk to the bottom. The following liquids should not be drunk if they were left overnight in an uncovered vessel: water, wine, milk, honey, and crushed garlic...

The normative Code of Jewish Law, the שולחן ערוך agreed, but added an important caveat:

שולחן ערוך יורה דעה הלכות מאכלי עובדי כוכבים סימן קטז סעיף א 

משקים שנתגלו, אסרום חכמים דחיישינן שמא שתה נחש מהם והטיל בהם ארס. ועכשיו שאין נחשים מצויים בינינו, מותר

The rabbis forbade drinking from liquids that were left uncovered,. They were concerned that a snake may have drunk from them and expelled some of its poison into them. But now that snakes are not commonly encountered, this is permitted. (Shulchan Aruch Yoreh De'ah 116:1)

So today it is permitted for us to drink from an uncovered pot, but only in a place that does not have a problem with poisonous snakes.  Which is not helpful. There are poisonous snakes in nearly every state in the US, resulting in about 2,000 human envenomations each year, and we have noted before that Israel has its own problem with snakes, including the Palestinian Viper.  The World Health Organization estimates that snakes kill between 20,000 and 94,000 people per year. So exactly where this leniency of the Shulchan Aruch might apply is not clear.

But is drinking snake venom indeed dangerous? Maybe not. In 2012 India Today reported that police in New Delhi had seized about half a liter of snake venom to be used "in high-end raves planned for Valentine's Day in and around the national capital." Apparently the venom, when ingested, produces a euphoric state. Who knew?

VIDEO EVIDENCE - DRINKING COBRA VENOM

It is really hard to find any peer-reviewed scientific studies about people drinking snake venom, because, um, it's a silly thing to do.  But that doesn't mean it hasn't been done. So where could we turn to find people doing silly things? YouTube of course.(The real action begins at 10:13).

Want more? Ok then. Here's another one. This time it involves drinking the venom directly from spitting snake. Apparently, these kind of human interest stories are popular in India. 

WHY IT IS SAFE TO DRINK SNAKE VENOM

If you are a diabetic and take insulin, or know someone who does, you may have wondered why the drug has to be injected. It would, after all, be much less bothersome to swallow an insulin pill than to inject insulin several times a day.  The reason is that insulin is a protein, and like all proteins, it is easily broken down by heat and, more importantly, by the acid environment in the stomach.  Our gastrointestinal tracts evolved to break down proteins into their building blocks - and they perform a wonderful job doing precisely that.

Like insulin, snake venom is a complex protein. And so, like insulin, it too is easily broken down in the very acidic environment of your stomach.  Of course, if intact venom gets into your bloodstream, it could kill you. But if you drink venom, then the intact protein never does get into your bloodstream. You don't need to be an Indian snake charmer to safely drink snake venom. You just need a working digestive system.

How snakes drink

In case you were wondering how we know how snakes drink, here is a diagrammatic view of the apparatus used to record the kinematics and water transport during drinking. The video camera was placed to the left. LED, light-emitting diode. From Cundall, D. Drinking in snakes: kinematic cycling and water transport. The Journal of Experimental Biology. 2000; 203, 2171–2185.

The Talmud was concerned that snakes leave venom in the water from which they drank, and that a person drinking from that water would then suffer from envenomation. As we have seen, this concern has no biological basis, although theoretically, if there was an open cut or ulcer in the mouth, ingested venom could get into the bloodstream and then cause its havoc.  But there is another reason why the talmudic concern is overstated.  Snakes, you see, don't leave any venom when they drink water.  As you may have noted from watching the first video, it takes a lot to get a snake to expel its venom - like sticking a blue pen in its mouth.  Venom is a snake's most precious commodity, and it has evolved to protect that commodity. Snakes only release venom when they are in danger, or ready to strike their prey, and not otherwise. Want a great example? The venomous rattlesnake. That species has evolved a warning rattle to tell would-be predators that if they get any closer, they will be bitten. This only makes evolutionary sense if it was in the snake's best interest to do everything possible to conserve its venom.

In a fascinating article on how snakes drink published in The Journal of Experimental Biology, David Cundall notes that a snake's tongue does not carry or move water, and that "in many snakes, the tongue does not visibly move during drinking." That leads to the conclusion that snakes are suction drinkers. And that makes them even less likely to leave any venom behind in the water.

So let's put this all together:

1. Snakes don't release their venom unless they are threatened or hunting. 

2. Snakes use suction when they drink water. Their mouths are not open, which is needed when they are expelling venom.

3. Snake venom is not dangerous when drunk.

4. (If somehow venom did get into the water, it would be greatly diluted.)

So there is no danger if you were to drink from wine from which a venomous snake had drunk. None. But this was not known to the rabbis of the Talmud, for whom the advice to stay away from all things snake made for a very good public health message.

[Repost in part from Bava Kamma 115.]

Bava Basra 95 ~ The Smallest Ramanujan Taxicab Number

This post is for tomorrow’s page of Talmud to be studied, which is page 1,729 of the Babylonian Talmud. Print it up now and enjoy, and Shabbat Shalom from Talmudology.

The number of tomorrow’s daf, (Bava Basra) 95, has some special mathematical properties. For example, it is a Thabit number, (also called a 3-2-1 number) which is an integer that is of the form 3 · 2ⁿ - 1. But there is another mathematical curiosity about tomorrow’s page number. Starting from the beginning, it is page number 1,729 of the Babylonian Talmud. And 1,729 is the smallest Ramanujan Taxicab Number, a number that can be written as the sum of two cubes: (1³ + 12³=1729.) In two different ways: (9³ + 10³=1729).*

[*These numbers are also known as Hardy-Ramanujan numbers. Also, to be precise, they are numbers that can be can be written as the sum of two cubes using positive integers. Let’s keep going.]

Here is one version of the story of how these numbers were discovered:

Curious properties sometimes lurk within seemingly undistinguished numbers. 1729 sparked one of maths most famous anecdotes: a young Indian, Srinivasa Ramanujan, lay dying of TB in a London hospital. G.H. Hardy, the leading mathematician in England, visited him there. 'I came over in cab number 1729,' Hardy told Ramanujan. 'That seems a rather dull number to me.'

'Oh, no!' Ramanujan exclaimed. '1729 is the smallest number you can write as the sum of two cubes, in two different ways.' Most of us would use a computer to figure out that 1³ + 12³ = 9³ + 10³ = 1729. Ramanujan did it from his sickbed without blinking.

Mathematicians have mined his theorems ever since. ..Far more than just another number theory, 1729 is the first of the 'Ramanujan numbers' or taxicab numbers. Mathematicians are competing to search for more of them (with higher powers) and testing the strength of new computing technology. The search is seen as mathematics' current greatest challenge. Only recently, a lost bundle of Ramanujan's notebooks turned up in a Cambridge library setting maths off on a new voyage of discovery.

“Ramanujan, a largely self-taught mathematician, seemed to solve problems instinctively and said his formulas came to him in the form of visions from a Hindu goddess. During the height of British colonialism, he left his native India to become a protégé of mathematician G.H. Hardy at Cambridge University in England.”

— Emory University News Center, October 22, 2015.

In case you are wondering, this is the only page of the Talmud that is a taxi-cab number. (There is a machloket achronim [debate] as to whether 2 is a taxicab number. Some lists include it. Others don’t. Personally, I don’t think it counts, but my opinion on the matter is of zero mathematical importance.) The next one is 87,539,319.

Talmudology on the Parsha, Nitzavim~ I Have a Dream

דברים 30:12

כִּי הַמִּצְוָה הַזֹּאת אֲשֶׁר אָנֹכִי מְצַוְּךָ הַיּוֹם לֹא־נִפְלֵאת הִוא מִמְּךָ וְלֹא רְחֹקָה הִוא׃

לֹא בַשָּׁמַיִם הִוא לֵאמֹר מִי יַעֲלֶה־לָּנוּ הַשָּׁמַיְמָה וְיִקָּחֶהָ לָּנוּ וְיַשְׁמִעֵנוּ אֹתָהּ וְנַעֲשֶׂנָּה׃

Surely, this instruction which I enjoin upon you this day is not too baffling for you, nor is it beyond reach.It is not in the heavens, that you should say, “Who among us can go up to the heavens and get it for us and impart it to us, that we may observe it?”

Rashi, citing the statement of Avdimi bar Chama bar Dosa (Eruvin 55a) comments:

לא בשמים הוא. שֶׁאִלּוּ הָיְתָה בַשָּׁמַיִם, הָיִיתָ צָרִיךְ לַעֲלוֹת אַחֲרֶיהָ לְלָמְדָהּ

IT IS NOT IN HEAVEN — for were it in heaven it would still be your duty to go up after it and to learn it.

However, elsewhere (Bava Metziah 59b) the Talmud is very clear: when it comes to Jewish law, we keep “the heavens” out of it. When Rabbi Eliezar found himself losing a halakhic battle with his colleagues, he arranged for a series of miracles to prove that his ruling was correct. Here is what happened next:

עמד רבי יהושע על רגליו ואמר (דברים ל, יב) לא בשמים היא מאי לא בשמים היא אמר רבי ירמיה שכבר נתנה תורה מהר סיני אין אנו משגיחין בבת קול שכבר כתבת בהר סיני בתורה (שמות כג, ב) אחרי רבים להטות

Rabbi Yehoshua stood on his feet and said: It is written: “It is not in heaven” (Deuteronomy 30:12). The Gemara asks: What is the relevance of the phrase “It is not in heaven” in this context? Rabbi Yirmeya says: Since the Torah was already given at Mount Sinai, we do not regard a Divine Voice, as You already wrote at Mount Sinai, in the Torah: “After a majority to incline” (Exodus 23:2).

Rabbis who Dream and Decide

It is therefore somewhat surprising that this principle was forgotten when some rabbis declared that they had received halakhic rulings in their dreams. Some of them were noted by Ze’ev Zuckerman in his Otzar Pila’ot Hatorah, and this week on Talmudology we will take a closer look at rabbis who claim to have had God tell them directly how to rule.

First, let’s note that after Rabbi Eliezer’s claim of support via miracles, the earliest example of paksening (ruling) via dreams can be found in the writings of Natronai Ben Hilai Hacohen, known as Natronai the Gaon, who lived in Mesopotamia in the late 9th century and headed the Yeshiva in Sura. He was asked whether a person who converts out of Judaism may legally inherit his father’s property. Nope. “כך הראוני מן השמים שמשומד אינו ירוש אביו.” “This is what was taught to me from heaven: an apostate may not inherit his father.”

The Rashba

Shlomo ben Avraham ibn Aderet (1235-1310) was a Spanish rabbi who left a great many responsa (actually more than 3,000 according to this source). I counted at least 19 that have the phrase שהראוני מן השמים “as shown to me from heaven” in them. Here is the first responsum in which this phrase appears, shown in the red box.

שו"ת הרשב"א - א בני ברק, תשי"ח - תשי"ט

The Ra’avad

Abraham ben David (best known by his acronym Ra’avad, c.1125-1198) lived in Provence and is famous for his (sometimes quite hostile) commentary on the Mishneh Torah of Maimonides. In the Laws of the Lulav (8:8) Maimonides outlined the blemishes that render a myrtle (hadas) as useless. However, according to Maimonides, “a myrtle branch whose top is cut off is acceptable.” But that wasn’t how the Ra’avad ruled. And he had it on good authority:

הדס שנקטם וכו'. כתב הראב"ד ז"ל כבר הופיע רוח הקודש בבית מדרשנו מכמה שנים והעלינו שהוא פסול כסתם מתני'. ודברי רבי טרפון שאמר אפילו שלשתן קטומים כשר ענין אחר הוא ולא שנקטם ראשו והכל ברור בחבורנו ומקום הניחו לי מן השמים עכ"ל

The Holy Spirit (רוח הקודש) has appeared in our Bet Midrash (study hall) over a number of years and has ruled that such a myrtle is forbidden…

Shut Min Hashamayim - The Responsa From Heaven

The thirteenth century French kabbalist Jacob HaLevi of Marvège (יעקב הלוי ממרויש) took this heaven thing and cranked the volume up to 11. He wrote a series of responsa whose halakhic decisions, he claimed, were revealed to him in his dreams. He called the work, appropriately, “שאלות ותשובות מן השמים” - Questions and Answers From Heaven. In a fascinating article on the work, the late Israel Ta-Shema (1936-2004) wrote that it was cited as early as 1215 (in a book called Hamanhig by Avraham Hayarechi). It was used widely during the middle ages and “many important poskim [religious authorities] relied on it when ruling.”

The Magid Mesharim - The Preacher of RIGHTEOUSNESS

Not to be outdone, no less a personality than Yosef Karo (or Caro, 1488-1575), the author of the authoritative Shulchan Aruch, (Code of Jewish Law) also claimed to have been visited by heavenly creatures who would urge him on to new spiritual heights. He wrote a book about these encounters which he called Maggid Mesharim - The Preacher of Righteousness. Writing in the Jewish Encyclopdia, here is how Louis Ginzberg explained the book:

This book is a kind of diary in which Caro during a period of fifty years noted his discussions with his heavenly mentor, the personified Mishnah. …The discussions treat of various subjects. The maggid enjoins Caro to be modest in the extreme, to say his prayers with the utmost devotion, to be gentle and patient always. Especial stress is laid on asceticism; and Caro is often severely rebuked for taking more than one glass of wine, or for eating meat. Whenever Caro did not follow the severe instructions of his maggid, he suddenly heard its warning voice. His mentor also advised him in family affairs (p. 21b), told him what reputation he enjoyed in heaven, and praised or criticized his decisions in religious questions…

The present form of the "Maggid Mesharim" shows plainly that it was never intended for publication, being merely a collection of stray notes; nor does Caro's son Judah mention the book among his father's works. It is known, on the other hand, that during Caro's lifetime the cabalists believed his maggid to be actually existent …. The "Maggid Mesharim," furthermore, shows a knowledge of Caro's public and private life that no one could have possessed after his death; and the fact that the maggid promises things to its favorite that were never fulfilled—e.g., a martyr's death—proves that it is not the work of a forger, composed for Caro's glorification...

Some Halachik rulings determined by dreams

1. Is Balbuta Kosher?

   Balbuta was some kind of fish that shed its scales as it grew. (Perhaps it was this fish). Rabbi Ephraim of Regensburg (1110-1175) ruled that it was kosher, as had Rashi and his two famous grandsons Rashbam and Rabbenu Tam. According to the account of R. Baruch of Mainz (1150-1221) the night after R. Ephraim made his fishy ruling, he [Ephraim] had a dream

   “that he was being presented with a brimming plate of non-kosher crustaceans by an elderly man with a pleasant countenance, white hair, and a flowing white beard. The elderly man bid R. Ephraim to eat from this plate, but Ephraim adamantly (and even angrily) refused, explaining to the man that these were non-kosher sea creatures. The man responded, “These are as permitted (for consumption) as the non-kosher species (sherazim) that you allowed today.” When R. Ephraim awoke, he understood that Elijah the Prophet had appeared to him, and he refrained away from (eating) those fish from that day on (me-hayom va-hal’ah piresh me-hem)” (From here.)

2. Lung adhesions and kashrut

   R. Isaiah di Trani, known as the Rid (c.1180-c1250) ruled that certain lung adhesions that were found in a slaughtered animal rendered it treif, and as a result its meat could not be eaten. While he recognized that in general one may not be guided by dreams when reaching halakhic decisions (c.f. Sanhedrin 30a “דברי חלומות לא מעלין ולא מורידין”), the Rid also noted that Elijah the prophet had appeared to him in a dream and that Elihah supported the Rid’s position.

תשובות הריד, ירושלים 1975, #112

3. Paying a worker from the foods he collects

The Mishnah (Bava Metziah 118a) rules that a worker who is paid to collect straw and chafe (which is the husk surrounding a seed, and is generally discarded,) may refuse payment in the form of these items, since they are difficult to trade or exchange for other foods. In the Middle Ages the question arose as to whether this ruling is restricted to wheat and chafe mentioned specifically in the Mishnah, or is generalisable to other low quality items a worker is paid to collect.

One of the great medieval talmudists used a dream to decide the issue. Mordechai ben Hillel, known simply as “the Mordechai” (c.1250-1298) was a German posek whose rulings to this day are printed at the back of the standard editions of the Talmud. And here is his one of them:

מרדכי מסכת בבא קמא פרק ארבעה אבותֿ

ולמורי ר' מאיר נראה בחלום דוקא בתבן ובקש אבל במידי דאכילה כגון חטין ושעורין ואמר טול מה שעשית בשכרך שומעין לו, וכן פסק להלכה

My teacher R. Meir saw in a dream that only wheat and chafe can specifically be rejected by the worker. But regarding other edible commodities, such as wheat and barley, the hirer may say to the worker “take your wages from this produce.”

4. Is refraining for pride one of the 613 Mitzvot?

Among the earliest works of Jewish Law is that of Moses ben Jacob of Coucy, a 13th century French tosafist and disciple of Rabbi Yechiel of Paris. In 1247 he completed his Sefer Mitzvot Gadol, and he needed to decide whether the sin of pride (גאוה) was one of the 248 negative commandments found in the Torah. He decided it was, and listed it as “Negative Prohibition #64”:

ספר מצוות גדול לאוין, ס״ד

השמר לך פן תשכח את ה' אלהיך אזהרה שלא יתגאו בני ישראל כשהקדוש ברוך הוא משפיע להם טובה ויאמרו שבריוח שלהם ועמלם הרויחו כל זה ולא יחזיקו טובה להקב"ה מחמת גאונם שעל זה עונה זה המקרא ואומר גם בפ' ואתחנן ובתים טובים מלאים כל טוב אשר (מאת) [לא מלאת] וגומ' ואכלת ושבעת השמר לך פן תשכח וגו' וזה הפי' שפירשתי מפורש בסמוך פן תאכל ושבעת ובתים טובים תבנה וישבת ובקרך וצאנך ירביון וכסף וזהב ירבה לך וגומ' ורם לבבך ושכחת את ה' אלהיך המוציאך מארץ מצרים וגו' ואמרת בלבבך כחי ועוצם ידי עשה לי את החיל הזה וזכרת את ה' אלהיך כי הוא הנותן לך כח לעשות חיל ומכאן (ב) אזהרה שלא יתגאה האדם במה שחננו הבורא הן בממון הן ביופי הן בחכמה אלא יש לו להיות ענו מאד ושפל ברך לפני ה' אלהי' ואנשי' ולהודות לבוראו שחננו זה

Beware lest you forget the Lord your God." [Deuteronomy 4:23] This is a warning for the Israelites not to become arrogant when God blesses them with prosperity. They should not claim that all their success is due to their own efforts and hard work, thereby neglecting to acknowledge God's goodness due to their pride. This is what the verse addresses, as it also says in the portion of Va'etchanan, "Houses filled with all good things that you did not fill..." [Deuteronomy 6:11] and continues, "And you will eat and be satisfied, beware lest you forget the Lord your God." This interpretation is further explained nearby, "Lest you eat and be satisfied, and build good houses and live in them, and your cattle and sheep increase, and you gather silver and gold in abundance, and your heart becomes haughty, and you forget the Lord your God who brought you out of the land of Egypt..." and "You will say in your heart, 'My strength and the power of my hand made me all this wealth,' but you shall remember the Lord your God, for it is He who gives you the strength to make wealth." From here (b), there is a warning not to be arrogant about what God has granted, whether it is wealth, beauty, or wisdom. Rather, one should be very humble and lowly before the Lord, their God, and before people, and give thanks to their Creator for granting them these qualities.

Rather surprisingly, Moses then described how he had arrived this interpretation of the verse (Deut. 4:23) השמר לך פן תשכח - “Beware lest you forget the Lord your God."

וכשהגעתי להשלים ע"כ הלאוין וארא בחלום במראית הלילה הנה שכחת את העיקר השמר לך פן תשכח את ה' והתבוננתי עליו בבקר והנה יסוד גדול הוא ביראת השם הואלתי לחברו בעזרת יהיב חכמתא לחכימין

When I reached the completion of the prohibitions and saw in a dream at night that I had forgotten the principle, "Beware lest you forget the Lord," I considered it in the morning, and behold, it is a great foundation in the fear of the Lord. Therefore, I decided to include it, with the help of the One who grants wisdom to the wise…

Lo Bashamayim In Theory and Practice

There are many more examples I could share but let’s conclude with Ephraim Kanarfogel, University Professor of Jewish History, Literature and Law at Bernard Revel Graduate School of Jewish Studies and at Stern College for Women. He concludes his fascinating paper Dreams as a Determinant of Jewish Law and Practice in Northern Europe During the High Middle Ages (from where some of these examples were taken), with this thought:

In sum, the (surprisingly) positive or receptive attitude that a number of Tosafists expressed with respect to the potential impact of dreams on the halakhic process, as well as the differences between them about how such dreams should be evaluated and classified, had much in common with the surrounding host culture, even as the Tosafist attitudes were clearly a function of their own rabbinical and mystical sensibilities. As leading students and teachers of talmudic law, the Tosafists were surely cognizant of the principle, lo ba-shamayim hi, “it is not in heaven.” As religious authorities of their age, however, they were more than willing to entertain the possibility that heavenly, dream-like contra-texts could nonetheless contribute to the halakhic enterprise, and to Jewish life and practice more broadly.

Shabbat Shalom and sweet dreams (חלומות פז) from Talmudology

עד הניצחון

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