The Lord said to Moses: If anyone
sins and is unfaithful to the Lord... about something...stolen...or
he commits any such sin that people may do - when he thus sins, and
becomes guilty, he must return what he has stolen or taken by extortion.
He must make restitution in full, add a fifth of the value to it and
give it all to the owner... Leviticus 6:1-5 (NIV)