Leviticus 5:1-2

Revised Standard Version

5 “If any one sins in that he hears a public adjuration to testify and though he is a witness, whether he has seen or come to know the matter, yet does not speak, he shall bear his iniquity. ² Or if any one touches an unclean thing, whether the carcass of an unclean beast or a carcass of unclean cattle or a carcass of unclean swarming things, and it is hidden from him, and he has become unclean, he shall be guilty.