Leviticus 5:1, 4

“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 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.