Leviticus 5:1-3

1“If someone sins by failing to testify when he hears a public charge about something he has witnessed, whether he has seen it or learned of it, he shall bear the iniquity.

2Or if a person touches anything unclean—whether the carcass of any unclean wild animal or livestock or crawling creature—even if he is unaware of it, he is unclean and guilty.

3Or if he touches human uncleanness—anything by which one becomes unclean—even if he is unaware of it, when he realizes it, he is guilty.