The Gemara on Amud Beis tells us that Rav’s and Rav Chiyya’s wife would prepare cups of peeled barley grains for their husbands. The Gemara cites this as a proof that such an amount is not considered too large as to be processing the food for later instead of impromptu eating on the spot. When it is impromptu, certain leniencies apply in regard to preparing food for Yom Tov, as well as leniencies in tithing. 

Since Rav Chiyya was the elder and Rav’s teacher, there is something odd about the Gemara quoting Rav’s wife first, and then Rav Chiyya’s wife.

Rav’s and Rav Chiyya’s wives make another appearance in a different Gemara. Yevamos 63a tells us that Rav’s wife and Rav Chiyya’s wife were both difficult characters, especially, it would seem, in how they prepared food in a manner that they knew their husbands would not enjoy. The Gemara there discusses how Rav and Rav Chiyya each coped with their situation, keeping a balanced perspective so as not to lose their cool. Without getting into the details, an interesting feature of that Gemara is that the chronology is similar to our Gemara: We hear about Rav’s wife before we hear about Rav Chiyya’s, despite Rav Chiyya being the elder. It would seem that our Gemara, by using the same inverse order, is calling attention to the stories about their wives in Yevamos.

What could the correspondence be? I am not really sure. Drop me an email if you can come up with a good explanation.  Here are my incomplete thoughts. On the simplest level, we can see the chiddush is that even these wives who were not particularly interested in being kind to their husbands still prepared cups of barley kernels for their husbands. This would then strengthen the proof that such an amount is not considered too large to be considered processing and preparation, as opposed to impromptu eating, thus not a violation of Yom Tov and/or tithing requirements.

The romantic in me would like to think that this Gemara is the happy ending, that somehow in time, Rav’s and Rav Chiyya’s patience paid off, their relationship improved, and even they had shlom bayis, and eventually their wives were happy to prepare them food according to their wishes.