The Gemara relates how Benayahu ben Yehoyada studied the entire “Sifra D’bei Rav” in one short winter day, which Rashi explains as being Toras Kohanim. Since Benayahu lived during the first Beis Hamikdash, how could he have possibly learned Toras Kohanim which are Breisos compiled by the Tanaim generations later?
Brachos 18 – ברכות יח
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