The Philistines acknowledged Yahweh's superiority over Dagon, but they believed they could manipulate Him (v. 3). Guilt offerings were common in ancient Near Eastern religions.
"Ancient religious protocol mandated that the worshiper not approach his god(s) empty-handed (cf. Exod 23:15; Deut 16:16)."72
Evidently the reason the Philistines fashioned images of mice (v. 4) was there was some connection between rodents and the swellings the Philistines suffered.73This connection has led many interpreters to conclude that perhaps the Philistines had experienced something such as bubonic plague, which fleas living on rodents transmit. Bubonic plague causes swollen buboes or tumors.74Probably the Philistines intended that the models would trigger sympathetic magic. By sending the models out of their country they hoped the tumors and mice would depart too.
Yahweh had reduced the fertility of the crops of the Philistines as well as afflicting the people and their gods (v. 5). The Philistines remembered that this is what Yahweh had done to the Egyptians earlier (v. 6). The priests counselled the people not to harden their hearts as Pharaoh had done. Hardening the heart only brings divine retribution (cf. Josh. 7:19).
Milch cows (vv. 7, 10) are cows that are still nursing their calves. It would be very unusual for nursing cows to leave their young and head for a town some 10 miles away. Indeed the Philistines regarded this behavior as miraculous and indicative that Yahweh had been punishing them.
