Therefore you shall make images of your tumors, and images of your mice that mar the land; and you shall give glory to the God of Israel: peradventure he will lighten his hand from off you, and from off your gods, and from off your land.
Yahweh had reduced the fertility of the crops of the Philistines as well as afflicting the people and their gods (1 Samuel 6:5). The Philistines remembered that this is what Yahweh had done to the Egyptians earlier (1 Samuel 6:6). The priests counseled the people not to harden their hearts as Pharaoh had done. Hardening the heart only brings divine retribution (cf. Joshua 7:19).