In a discussion on the permissibility of assembling various items on Shabbat, there is this:
הַמַּחֲזִיר קְנֵה מְנוֹרָה בְּשַׁבָּת — חַיָּיב חַטָּאת. קְנֵה סַיָּידִין — לֹא יַחֲזִיר, וְאִם הֶחֱזִיר — פָּטוּר, אֲבָל אָסוּר
One who reassembles the branch of a disassembled candelabrum on Shabbat is liable to bring a sin-offering. With regard to the plasterer’s pole, which has several component parts, one may not reassemble it ab initio, and if he reassembled it, he is exempt from bringing a sin-offering, although it is prohibited.
It is from this rather uninteresting remark that a major modern prohibition was derived. The Chazon Ish, Rabbi Avrohom Yishaya Karelitz (1874-1953) was the undisputed leading Haredi rabbi of his period in Israel, where he lived from 1933 until his death. He gave an entirely new interpretation to this passage and insisted that it was the source for the prohibition against turning electrical devices on and off on Shabbat.
Since its widespread use, the rabbis had that turning on say an incandescent light bulb was prohibited on Shabbat because it violated the ban against burning (because the metal in the bulb would become white hot) or cooking (because the metal in the bulb would become soft under the heat). These certainly were considerations, but the Chazon Ish added a new twist on an old ban. Here it is in the original:
חזון איש - אורח חיים - מועד, סימן נ
In addition (to the prohibitions of cooking or burning) there is also the probation against fixing an object (מתקן כלי), since by turning on the switch it allows the circuit to become complete and the electric current can then flow. This is close to the prohibition against building which comes from the Torah, for he is fixing an object…
The source text for this ruling of the Chazon Ish is in today’s page of Talmud - the one with which we opened. Here is his explanation of the Talmud:
In Shabbat 47a we read “With regard to the plasterer’s pole, which has several component parts, one may not reassemble it. If nevertheless he did reassemble it, he is exempt from bringing a sin-offering, although it is prohibited.” It would appear that the ruling regarding the plasterer’s pole is comparable to its ruling regarding the pole of a lamp as appears in the prior clause, in that we are discussing attaching the pieces tightly, and nonetheless in the case of a plasterer’s pole one is exempt from the biblical violation of Shabbat. The reason is that the lamp is primarily used assembled, and when one disassembles it, it is not in order to use it but rather for a different purpose. However, the plasterer’s pole has two usable forms: to reach a low place a long pole is unsuitable, and to reach a high place a short pole is unsuitable. Thus, when one lengthens it temporarily, even if it is tightly joined, it is like stacking one tool on another to reach a high place and it is never really designated a “long pole.”
Here is how Dan Margulis, rabbi of the Riverdale Minyan explained the thinking of the Chazon Ish in his recent article on this topic published on The Lehrhaus:
As the Hazon Ish explains the Tosefta’s cases, it is prohibited to build a new tool or device on Shabbat because of “building.” Tools constructed of component parts which are then joined tightly are problematic for this reason. However, if the tool has two useful states—e.g. a plasterer’s pole which is used in both a long and short configuration—then no biblical violation is ever violated, since although the pieces are tightly joined, the tool always exists in an incomplete state of sometimes-short-sometimes-long.
In order to claim that the use of electricity on Shabbat constitutes a biblical violation, the Hazon Ish argues that (a) the joining of parts involved is considered “tight,” (b) that any electrical device is more similar to the lamp-pole (with one useful state) than the plasterer’s pole (with two interchangeable useful states), and, most importantly, (c) that this is an apt analogy to use as the basis for an entire model for the use of electricity in general…
The Hazon Ish claims that any electrical device is considered by Halakhah to be broken when the current is not flowing within it, since the “object” does not have the “form” necessary to be useful in the way in which it is normally used. When the electric current is connected to the “object” and its electrical components are activated, it attains the “form” necessary to become useful. In the case of the plasterer’s pole, the two lengths of wood which comprise the long handle are both objects. According to the Hazon Ish joining two objects together is a less intrinsic change than joining together an object and the electrical power which changes its form. Thus, the act of causing the current to flow through the electrical components constitutes an act of building the device itself—transforming it from a form in which it was unusable to a form in which it is usable…
And so, as Rabbi Margulis concludes, the Chazon Ish ruled that “enabling electrical current to flow through an electrical device currently powered down constituted building or repairing that device from a useless or unusable state to a useful one.” What it also important to note is that using a device “which remains on, even though its normal use involves opening and closing thousands of circuits is not the sort of boneh the Hazon Ish was concerned with.” This is important since it informs other rulings about using computers or smart watches on Shabbat that have been turned on earlier.
The operation of any electronic device involves the opening and closing of many circuits in the thousands or millions of transistors needed to complete even basic computational functions. However, since a transistor performs calculations and stores data with both the “on” and “off” states playing necessary and useful roles, the Hazon Ish would concede within his own paradigm that the operation of these electronics cannot possibly constitute a biblical violation of Shabbat, since their function is closer to the more lenient case of the plasterer’s pole than the more stringent case of the lamp-pole. Further, since the device as a whole remains on the entire time, and is never “dead” or without its tzurah, there can be no biblical violation of boneh as the Hazon Ish described in the normal use of an electronic device which remains on.
And all this from the simple observation of the Talmud about some guy plastering.
