Leviticus 6:4-5

6:4 when it happens that he sins and he is found guilty, then he must return whatever he had stolen, or whatever he had extorted, or the thing that he had held in trust, or the lost thing that he had found, 6:5 or anything about which he swears falsely. He must restore it in full and add one fifth to it; he must give it to its owner when he is found guilty.