1. When a person sins in hearing the spoken oath, and he is a witness, whether he saw or knew about the incident, if he does not report it, he bears guilt.
2. Or when a person touches any ceremonially unclean thing, whether it is a carcass of unclean wildlife, or a carcass of an unclean domesticated animal, or the carcass of an unclean crawling thing, and he did not realize it, then he has become unclean and guilty.