The Gemara records on 47a the story where Yehoshua Ben Perachiya called his talmid a "rasha" for a mistake the talmid made.Then the Gemara says the student would go back to yehoshua every day to ask mechila but still yehoshua ben perachiya would not accept him or forgive him. But why didnt yehoshua ben perachiya forgive his talmid after all the talmid came back many times and doesnt the Gemara in the last perek of Yoma teach how one should forgive someone when they ask forgiveness and emulate hakadosh baruch hoo just as he is forgiving so too we should be. Furthermore, the Gemara also says one should be "maavir al midotov" in Rosh Hashana 17a i believe "kol hamavir al midotov maavirin lo al kol peshaav"- we should forgive on matters against us, so why did Yehoshua ben perichiya stay very firm and not give mechila to his student?
Secondly it appears from our Gemara the talmid asked mechila many times more than 3 but doesnt the Gemara in Yoma there say if one asked for mechila 3 times one should not ask more because that is enough and hashem will forgive?
Daniel Fishman, Lawrence America
First, the Beraisa itself, that you refer to, criticizes Rebbi Yehoshua ben Perachiyah's behavior as being too unforgiving (he "pushed him off with both hands" instead of "pushing off with the left hand and drawing close with the right").
Second, most of the Rishonim (Rif, Rambam, and Rosh among others) rule that that there is no limit to the number of times that a Talmid must ask forgiveness from his Rav (see Beis Yosef to Tur, Orach Chaim 606; Rashi is a dissenting opinion).
Third, while the Gemara in Yoma 87b says that even a Rav should be forgiving to his Talmid, it also says that if the Rav has good reason to withhold his Mechilah, he may do so (see the Bach to Tur, OC 606). We have to assume that a Tzadik like Rebbi Yehoshua ben Perachiyah was withholding his Mechilah for good reason, and his inflexibility was not gratuitous.
Kol Tuv,
Yonasan Sigler