Weekly Torah Study: Vayakhel 5782/2022

A Midrashic approach to the verses ויקהל משה: The commandment for Moses to assemble all the people at this point was to compensate for the time Aaron had assembled all the people at the time of the golden calf. This new assembly was to atone for the previous assembly which had such tragic results. Similarly, the words Moses spoke at this time were intended to diffuse the impression Aaron’s words had left behind when he addressed the people at that ill-fated assembly (32,1). The wording אלה הדברים, “these are the words,” were meant to counteract the words אלה אלוקיך ישראל, “these are your gods O Israel,” spoken at the time when Aaron assembled the people. The gold donated for the construction of the Tabernacle was to atone for the gold donated for making the golden calf.
-Rabbenu Bahya (On 35:1)

Rabbi Dr. Yoel Bin-Nun
https://www.thetorah.com/article/the-textual-source-39-melachot-shabbat
Investigating further
Nevertheless, the variant inspires me to offer a novel suggestion. As pointed out above, if we count every form of the word melacha as it appears in the Torah we get the number 65, so this is a dead end. But perhaps the original midrash only counted two forms of the word, but not the two in that variant. What do we get if we count only the forms מלאכה and מלאכתו but ignore “מלאכת”? (This makes sense, since this last form generally appears in the context of Yom Tov and not Shabbat anyway.) The number we get is 40!
Since the number of melachot on Shabbat is 39 and not 40, the next part of the Talmudic passage works well. The rabbis were ambivalent about counting two of the examples and ended up counting only one of them, yielding the number 39. Considering how well this works out, I believe that the original version of this midrash made use of only these two forms (מלאכה and מלאכתו) and that the printed version as well as the manuscript version are both errors. (Errors like these are hardly surprising, since the meaning of the midrash was probably lost relatively early.)...
The two detailed lists that appear at the beginning and end of the account of building the Tabernacle inspired the choice of 39 as a number set in stone for the prohibited forms of melacha on Shabbat. Virtually all treatments of Shabbat law force themselves into this rubric. This, in my opinion, is the meaning of Rabbi [Yehudah haNasi]’s statement, quoted in the Mechilta, as well as the statement of R. Chanina bar Chama in the Babylonian Talmud (Shabbat 49b):
When the Mishna sites 40 melachot minus one—to what does this correspond? R. Chanina bar Chama said to them: “It corresponds to the items of service [built for] the Tabernacle.”
As I argued above, I believe that this is also how we should understand the words of R. Yossi b’ R. Chanina in the Jerusalem Talmud (Shabbat 7:2), as well as the positions of Rabbi [Yehudah HaNasi] (Shabbat 97b) and Rabbi Nathan (Shabbat 70a) in the Babylonian Talmud.

https://www.zomet.org.il/eng/?CategoryID=199&ArticleID=58
In practice, it is generally assumed that electrical devices should not be turned on or off on Shabbat and the holidays but no specific attempts have been made to determine the basis for the prohibitions. If turning electrical currents on and off would be allowed, the appearance of Shabbat would be completely different than it is today, since almost anything can be accomplished today using electricity, and there would no longer be any apparent difference between Shabbat and the other days of the week. The discussions of the reasons for prohibiting the use of electricity are mostly relevant in boundary cases, such as medicine and where there are security concerns.