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.

Leviticus 5:4

5:4 or when a person swears an oath, speaking thoughtlessly with his lips, whether to do evil or to do good, with regard to anything which the individual might speak thoughtlessly in an oath, even if he did not realize it, but he himself has later come to know it and is guilty with regard to one of these oaths –