Most of the Torah is darshoned by Chazal or the Sanhedrin as a combination of two sources: 1) Mesorah going back to Moshe Rabbeinu, and 2) the י"ג midos by which the drashos are derived. They are used all over Shas to study and learn all the laws of the Torah.

Shabbos seems to have a unique third source, 3) the construction of the Mishkan. Throughout the gemara, Chazal use this additional tool of examining the engineering steps involved in constructing the Mishkan. Here and there, they discuss what those steps were, and use them to understand the ל"ט מלאכות that were involved. Roughly speaking, part of learning Shabbos is to sit down with engineers and figure out exactly how to build a Mishkan.


גְּמָ׳ כׇּל שֶׁהוּא לְמַאי חַזְיָא? אָמַר רַבִּי יִרְמְיָה: שֶׁכֵּן עָנִי חוֹפֵר גּוּמָּא לְהַצְנִיעַ בָּהּ פְּרוּטוֹתָיו. דִּכְווֹתַהּ גַּבֵּי מִשְׁכָּן, שֶׁכֵּן תּוֹפְרֵי יְרִיעוֹת חוֹפְרִין גּוּמָּא לְהַצְנִיעַ בָּהּ מַחֲטֵיהֶן. אַבָּיֵי אָמַר: כֵּיוָן דְּמִשַּׁתְּכִי לָא עָבְדִי הָכִי. אֶלָּא, שֶׁכֵּן עָנִי עוֹשֶׂה פִּיטְפּוּטֵי כִּירָה קְטַנָּה לִשְׁפּוֹת עָלֶיהָ קְדֵירָה קְטַנָּה. דִּכְווֹתַהּ גַּבֵּי מִשְׁכָּן, מְבַשְּׁלֵי סַמָּנִין לִצְבּוֹעַ יְרִיעוֹת שֶׁחָסְרָה מְלַאכְתָּן, עוֹשִׂין פִּיטְפּוּטֵי כִּירָה קְטַנָּה לִשְׁפּוֹת עָלֶיהָ יוֹרָה קְטַנָּה.
GEMARA: The Gemara asks: With regard to any small amount of building, for what use is it suited? Rabbi Yirmeya said: As a poor person digs a hole in the floor of his house in which to hide his coins. Digging a hole in the floor of a house is an act of building. The corresponding situation in the Tabernacle was as those who sewed curtains in the Tabernacle dug holes in which to hide their needles. Abaye said: Since needles rust in the ground, they did not do so. The Gemara seeks a different example of small-scale building that is significant. Rather, an example is that a poor person makes legs for a small stove to place a small pot on it. The corresponding situation in the Tabernacle was with regard to those who cooked herbs used to dye curtains, whose dyeing process was lacking a small amount for completion. At that point, it was not worth the effort to cook a large quantity of dye, and so they would make legs for a small stove upon which to place a small cauldron to cook a small bit of dye to finish the job.
רַב אַחָא בַּר יַעֲקֹב אָמַר: אֵין עֲנִיּוּת בִּמְקוֹם עֲשִׁירוּת. אֶלָּא, שֶׁכֵּן בַּעַל הַבַּיִת שֶׁיֵּשׁ לוֹ נֶקֶב בְּבִירָתוֹ וְסוֹתְמוֹ, דִּכְווֹתַהּ גַּבֵּי מִשְׁכָּן, שֶׁכֵּן קֶרֶשׁ שֶׁנָּפְלָה בּוֹ דַּרְנָא — מַטִּיף לְתוֹכָהּ אֲבָר וְסוֹתְמוֹ.
Rav Aḥa bar Ya’akov said: There is no poverty in a place of wealth. In the Tabernacle, actions are not performed on a small scale or in parsimonious quantities; they were performed generously. Those who cooked dyes in the Tabernacle had no use for small crucibles. Rather, an example of significant small-scale building is a homeowner who has a small hole in his house and seals it. The corresponding situation in the Tabernacle was with regard to a beam that was set upon by a worm that bore a hole into it; one pours lead into the hole and seals it.

My question is, Do we know of major changes in technology from the time of the Torah and building of Mishkan, to the time of writing the Mishnah/Gemara? I don't really doubt that people have been planting, and plowing, and harvesting from time immemorial. But what about some of the more subtle and confusing melachos like the ones involved in weaving? Do we know when שני בתי נירין were invented , etc.?

Are there any melachos for which this is a significant issue?

  • Can you provide an example or two of the phenomenon you're describing? And maybe show how such discussions cannot be understood as points of mesorah?
    – Joel K
    Mar 12, 2023 at 8:34
  • @JoelK Good point, I'll look. I certainly can't prove that they were not mesorah, just that to me they looked like the chachmei hagemara making statements about engineering steps.
    – MichoelR
    Mar 12, 2023 at 10:49
  • In a broader sense -- Rabbi Hershel Schachter has said he's open to the possibility that certain halachos locked in at the conclusion of the Talmud, based on the science they had at their day. Rabbi J David Bleich has a different suggestion -- that terms used when the Torah was given were intended -- "as this means to you, here and now." E.g. "don't kill animals on Shabbos" meant "don't kill things that you, as of this year [3500 years ago], understand to be animals." The problem is, as you stated, that technology may have changed between then and the Talmud.
    – Shalom
    Mar 12, 2023 at 11:38
  • 2
    I think Rabbi Ribiat's book actually does go through the steps of weaving and show that while the cool loom picture we've all seen in Rabbi Chait's illustrated book best describes the melachos, the way they were done in the desert does hit them all, but in less sophisticated ways.
    – Shalom
    Mar 12, 2023 at 11:40
  • @JoelK Okay, I found one.
    – MichoelR
    Mar 12, 2023 at 12:09


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