Leviticus 4:20

4:20 He must do with the rest of the bull just as he did with the bull of the sin offering; this is what he must do with it. So the priest will make atonement on their behalf and they will be forgiven.

Numbers 15:28

15:28 And the priest must make atonement for the person who sins unintentionally – when he sins unintentionally before the Lord – to make atonement for him, and he will be forgiven.