Who should one credit? A question on the Bartenura

Question

This question might be larger than just on the Bartenura, but it was a passage in his commentary on the Mishna that inspired it:

In Menachot 8:7, the mishna states that the Temple treasurer would watch the pouring of wine for libations in order to check that there was neither froth nor sediment in it, and that he would strike with his stick (perhaps against the side of the barrel) once it was time to stop pouring. The Bartenura comments on this, suggesting that the reason that he used a stick rather than his voice is that speech is harmful to wine (לפי שהדבור קשה ליין).

He credits this idea to his teachers (...ורבותי פירשו), but also acknowledges that it's found in the gemara (והכי מפרש בגמרא...). In fact, it appears in the gemara almost exactly as the Bartenura transcribed it:

אמר רבי יוחנן כשם שהדיבור יפה לבשמים כך דיבור רע ליין

Rabbi Yohanan said: Just as speech is good for [the grinding of] herbs, so is speech harmful to [the pouring of] wine.

• Menachot 87a (≈ Keritot 6b)

My question is: if the gemara provides this explanation explicitly, why did the Bartenura credit it to his teachers? And if the point was merely to show honour to his own rabbonim, why would one ever credit something to the gemara if they heard it from their teacher first?

Answer 1

It appears that he learned it from his teachers at the time he was learning mishnayos. Only later did he learn it from the gemara itself. Thus he credited the ones who taught him (and may have referenced the gemara). We see in the gemara that at times it credits Rav A and then quotes him as saying that he heard it from Rav B. We first give the credit to the one that we learned it from.

One should say who one heard it from first, and then give the ultimate source so that others can see where it came from.

I have given answers that my Rav gave an answer and cited a particular source when he did so.