Leviticus 5:1-2

New Revised Standard Version, Anglicised

5 When any of you sin in that you have heard a public adjuration to testify and—though able to testify as one who has seen or learned of the matter—do not speak up, you are subject to punishment. ² Or when any of you touch any unclean thing—whether the carcass of an unclean beast or the carcass of unclean livestock or the carcass of an unclean swarming thing—and are unaware of it, you have become unclean, and are guilty.