On today’s daf, the rabbis are in the midst of a discussion about an issue raised in the first mishnah of Tractate Ketubot — namely, which days are permissible to hold weddings. In response to a question about why a marriage can’t be celebrated and consummated on a Saturday night, Rabbi Zeira says it’s “because of calculations” —meaning, those involved in planning a Saturday night wedding could easily get drawn into last-minute preparations and thus wind up conducting weekday business on Shabbat. To prevent this, the rabbis prohibited having weddings on Saturday night.
Abaye challenges Rabbi Zeira’s reasoning, citing a teaching of Rav Hisda and Rav Hamnuna:
Calculations for a mitzvah, it is permitted to reckon them on Shabbat.
Since getting married is a mitzvah, Rav Hisda and Rav Hamnuna say it is OK to engage in activities related to the celebration on Shabbat. So Rabbi Zeira’s explanation can’t be the reason that Saturday night weddings are prohibited by the Talmud.
Rather than continuing to probe Rabbi Zeira’s reasoning for the ban on Saturday night weddings, the Talmud launches into a tangent about other normally proscribed activities one is permitted to perform on Shabbat:
Rabbi Elazar said: One may allocate charity to the poor on Shabbat.
Rabbi Ya’akov said that Rabbi Yohanan said: One goes to synagogues and study halls to supervise matters affecting the multitudes on Shabbat.
Rabbi Ya’akov bar Idi said that Rabbi Yohanan said: One supervises matters of saving a life on Shabbat.
Rabbi Shmuel bar Nahmani said that Rabbi Yohanan said: One goes to theaters and circuses to supervise matters affecting the multitudes on Shabbat.
The sage of the school of Menashya taught: One makes matches for a young girl to be betrothed on Shabbat, and one may make arrangements for a young boy to teach him Torah and to teach him a craft.
If this list seems familiar, that’s because it is: The same list appeared on Shabbat 150, where it is brought to support the assertion that on Shabbat, one is allowed to talk about certain activities that are normally forbidden.
Encountering a passage that also appears on another page of Talmud reminds us that the Gemara draws from a wellspring of rabbinic materials that is wider and deeper than the Talmud itself. Those who assembled the text of the Talmud drew from a range of inherited traditions and texts to form the work that we read today.
We leave it to the Talmud professors to figure out whether the editor of Ketubot 5 lifted this passage from Shabbat 150, or vice versa, or if they both were quoting from a third source. When they do, we’ll be able to determine if their findings shed new light on how we understand the material.
But you don’t need to wait for the professors. If you read something that sounds familiar, you can check to see if it appears elsewhere by looking at the notes in the margin of a traditional page of Talmud or by utilizing the embedded links in Sefaria’s online edition. And you can do your own research by looking to see if the source is used in a similar or a vastly different way. If you find something interesting, check with your local Talmud professor to see if you are on to something.
In case you’re wondering, the Gemara eventually concludes that the reason one can’t host a wedding on Saturday night is due to a rabbinic decree to prevent people from slaughtering animals on Shabbat in order to serve them at the wedding feast. And in case you’re wondering if this rule still applies today, the Shulchan Aruch says that “there are some who forbid” getting married on Saturday night for fear of violating Shabbat with last-minute preparations. This implies that there are some who permit it, which might be good news for those of you planning a Saturday night wedding.
Read all of Ketubot 5 on Sefaria.