I Samuel 6:3

3 They answered, "If you return the ark of the god of Israel, do not send it back to him without a gift; by all means send a guilt offering to him. Then you will be healed, and you will know why his hand has not been lifted from you."

3 And they said, If you send away the ark of the God of Israel, do not send it without an offering, but send him a sin-offering with it: then you will have peace again, and it will be clear to you why the weight of his hand has not been lifted from you.