Leviticus 5:1-4, 17

“When someone sins in any of these ways: If he has seen, heard, or known about something he has witnessed, and did not respond to a public call to testify, he will bear his iniquity.  Or 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.  Or 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. Or 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.

“If someone sins and without knowing it violates any of the LORD’s commands concerning anything prohibited, he is guilty, and he will bear his iniquity.