Leviticus 5:1, 6

“If you are called to testify about something you have seen or that you know about, it is sinful to refuse to testify, and you will be punished for your sin.

Then you must bring to the LORD as the penalty for your sin a female from the flock, either a sheep or a goat. This is a sin offering with which the priest will purify you from your sin, making you right with the LORD.