Leviticus 5:2-7

2Or if someone touches anything unclean  — a carcass of an unclean wild animal, or unclean livestock, or an unclean swarming creature  — without being aware of it, he is unclean and incurs guilt.

3Or if he touches human uncleanness  — any uncleanness by which one can become defiled  — without being aware of it, but later recognizes it, he incurs guilt.

4Or if someone swears rashly to do what is good or evil — concerning anything a person may speak rashly in an oath — without being aware of it, but later recognizes it, he incurs guilt in such an instance.

5If someone incurs guilt in one of these cases, he is to confess he has committed that sin.

6He must bring his penalty for guilt for the sin he has committed to the Lord: a female lamb or goat from the flock as a sin offering. In this way the priest will make atonement on his behalf for his sin.

7“But if he cannot afford an animal from the flock, then he may bring to the Lord two turtledoves or two young pigeons as penalty for guilt for his sin — one as a sin offering and the other as a burnt offering.