Bava Batra 115A

איתיביה רבי יוחנן לרבי יהודה בן שמעון: האשה את בנה, והאשה את בעלה, ואחי האם ⁠– מנחילין ולא נוחלין! אמר ליה: משנתנו, איני יודע מי שנאה.

R' Yoḥanan raised an objection to the opinion of R' Yehuda ben Shimon from the Mishnah, which teaches: A woman with regard to her son, a woman with regard to her husband, and maternal uncles all bequeath to their respective relatives but do not inherit from them. The Mishnah states explicitly that a mother does not inherit her son’s property. R' Yehuda ben Shimon said to him: With regard to our Mishnah, I do not know who taught it, i.e., I am not aware of any tanna who concurs with its ruling and it is not the accepted halakha.

ולימא ליה: רבי זכריה בן הקצב היא, דלא דריש ״מטות״!

The Talmud asks: But let R' Yoḥanan say to R' Yehuda ben Shimon that the Mishnah is written in accordance with the opinion of R' Zekharya ben HaKatzav, who, as noted on page 111a, does not derive the halakha that sons precede daughters with regard to the inheritance of their mother from the word “tribes.” Since R' Yehuda ben Shimon’s ruling is based on a derivation from the word “tribes,” it stands to reason that R' Zekharya disagrees with R' Yehuda ben Shimon, and the ruling of the Mishnah is in accordance with R' Zekharya’s opinion.

לא מיתוקמא מתניתין כרבי זכריה בן הקצב; דקתני: ״ובני אחות״, ותנא: ״בני אחות״⁠ – ולא בנות אחות. ואמרינן: למאי הלכתא? ואמר רב ששת: לקדם.

The Talmud answers: The Mishnah cannot be interpreted in accordance with the opinion of R' Zekharya ben HaKatzav, as it teaches: And the sons of a sister inherit but do not bequeath, and a Sage taught that the Mishnah is referring only to sons of a sister and not to daughters of a sister, and we say: With regard to what halakha is there a distinction between the sons and daughters of a sister? And Rav Sheshet said: The distinction is meant to teach that where there are sons as well, they precede the daughters in inheriting from their maternal uncle.