Leviticus 5:2-3, 6-7, 18-19

or if anyone touches an unclean thing, whether a carcass of an unclean wild animal or a carcass of unclean livestock or a carcass of unclean swarming things, and it is hidden from him and he has become unclean, and he realizes his guilt; or if he touches human uncleanness, of whatever sort the uncleanness may be with which one becomes unclean, and it is hidden from him, when he comes to know it, and realizes his guilt

he shall bring to the LORD as his compensation for the sin that he has committed, a female from the flock, a lamb or a goat, for a sin offering. And the priest shall make atonement for him for his sin. “But if he cannot afford a lamb, then he shall bring to the LORD as his compensation for the sin that he has committed two turtledoves or two pigeons, one for a sin offering and the other for a burnt offering.

He shall bring to the priest a ram without blemish out of the flock, or its equivalent, for a guilt offering, and the priest shall make atonement for him for the mistake that he made unintentionally, and he shall be forgiven. It is a guilt offering; he has indeed incurred guilt before the LORD.”