Numbers 5:7-9

7then he shall confess the sin which he has committed, and he shall make restitution for his wrong in full, and add a fifth to it, and give it to [the person] whom he has wronged.

8But if the man [who was wronged] has no redeemer (relative) to whom the restitution may be made, it is to be given to the Lord for the priest, besides the ram of atonement with which atonement is made for the offender.

9Also every contribution pertaining to all the holy gifts of the Israelites which they offer to the priest, shall be his.