The Eighteen Measures, Part 2: Another Upper Room

The Mishnah, tractate Shabbat 1:4, and its corresponding passage in the Babylonian Talmud (folios 13b-17b), present a strange puzzle to those who study it deeply.  Let us begin with the Mishnah passage that is discussed in the Gemara: These are some of the laws which they stated in the upper room of Hananiah b. Hezekiah …