Leviticus 5:1

Additional Sin Offering Regulations

5:1 “‘When a person sins in that he hears a public curse against one who fails to testify and he is a witness (he either saw or knew what had happened) and he does not make it known, then he will bear his punishment for iniquity.

Leviticus 5:6

5:6 and he must bring his penalty for guilt to the Lord for his sin that he has committed, a female from the flock, whether a female sheep or a female goat, for a sin offering. So the priest will make atonement on his behalf for his sin.