We can imagine the Philistines boasting as they brought the ark to their land and put it in their idol temple.
V.3 But the next morning their idol had fallen down before the ark of God! They lift up the idol, Dagon, and set it back in its place. It was God Who caused this.
V.4 The next morning the idol has fallen down and its head and its hands have broken off!
V.6 God will not permit His holy ark to rest in a heathen temple, and more than that, there are plagues among the Philistines and they are afraid to keep the ark any longer.
V.8 Instead of repenting and sending the ark back to Israel, they just send it to another part of their own country.
V.9-10 Again the Lord brings plagues and suffering upon these heathen. No doubt they were afraid to destroy the ark, for though they were heathen and worshipped idols, yet they knew that the God of Israel was the true and living God. 1 Samuel 4:77And the Philistines were afraid, for they said, God is come into the camp. And they said, Woe unto us! for there hath not been such a thing heretofore. (1 Samuel 4:7) confirms this.