Rav Yosef Berger shlit"a mentioned last night the shita of the Gra, that Aharon was allowed to do the (full) avodah of Yom Kippur whenever he wanted. Whereas, all other cohanim gedolim could only do it on Yom Kippur. The Rashash actually mentions this in his very first comment on the gemara in the masechta, and brings two midrashim in support.
So I was wondering from the gemara here on daf 5a
But according to the Gra it's not superfluous at all. On the contrary, this is the whole point. The whole parsha talks about Aharon and describes his avodah, and never mentions Yom Kippur. Then it comes along at the end and says that his son will do the avodah too - but only on Yom Kippur, as that final section begins
So I was wondering from the gemara here on daf 5a
וכפר הכהן אשר ימשח אתו ואשר ימלא את ידו לכהן תחת אביו, מה תלמוד לומר
ופירש"י אם ללמד שתהיה עבודה בכהן גדול ־ והלא כל הפרשה באהרן נאמרה, בזאת יבא אהרן, ונתן אהרן, והקריב אהרן, ובא אהרן
So Rashi says that the section saying that Aharon's sons will do the avodah after him is completely superfluous; after all, the parsha talks about Aharon the whole time, so we would know that his son the cohen gadol will do the same.ופירש"י אם ללמד שתהיה עבודה בכהן גדול ־ והלא כל הפרשה באהרן נאמרה, בזאת יבא אהרן, ונתן אהרן, והקריב אהרן, ובא אהרן
But according to the Gra it's not superfluous at all. On the contrary, this is the whole point. The whole parsha talks about Aharon and describes his avodah, and never mentions Yom Kippur. Then it comes along at the end and says that his son will do the avodah too - but only on Yom Kippur, as that final section begins
והיתה לכם לחקת עולם בחדש השביעי בעשור לחדש
So what is the gemara asking, מה תלמוד לומר?