1 Samuel 6:3
And they said, If ye send away the ark of the God of Israel, send it not empty; but in any wise return him a trespass offering: then ye shall be healed, and it shall be known to you why his hand is not removed from you.
Cross-references
In 1 Samuel 6:9, the test with the cows follows this instruction, using the guilt offering as part of discerning God's hand.
In 1 Samuel 5:7, the Philistines first recognize God's heavy hand, prompting the consultation that leads to this guilt offering advice.
In 1 Samuel 5:9, the plague in Gath shows the heavy hand; this guilt offering is meant to heal that affliction.
In 1 Samuel 5:11, the rulers demand to send the ark away; this verse seeks the proper method, including a guilt offering.
Leviticus 5:6 defines the guilt offering (asham) that the Philistines are instructed to send — a direct ritual parallel.
Leviticus 5:15-19 specifically addresses guilt offerings for unintentional sins against holy things — exactly the Philistines' situation with the Ark.
Leviticus 6:6 describes the guilt offering of a ram — the same type of offering the Philistines are told to send.
In Leviticus 7:1-7, the guilt offering law detailed shows the Philistines adapting Israelite concepts to appease God's anger.