Leviticus 16:3

3 “This is how Aaron is to enter the Most Holy Place: He must first bring a young bull for a sin offeringa and a ram for a burnt offering.

Read Leviticus 16:3 Using Other Translations

Thus shall Aaron come into the holy place: with a young bullock for a sin offering, and a ram for a burnt offering.
But in this way Aaron shall come into the Holy Place: with a bull from the herd for a sin offering and a ram for a burnt offering.
“When Aaron enters the sanctuary area, he must follow these instructions fully. He must bring a young bull for a sin offering and a ram for a burnt offering.