Judges 1:18

Judah took — It is only said, they took the cities, and probably contented themselves with making them tributary; but it is not said that they slew the people, as they ought to have done; and as it is said of the other cities here. And the people being thus spared, did by God's just judgment recover their strength, and expel the Jews out of their cities. It is farther observable, that Ekron here taken, was one of Dan's cities, Joshua 19:43, and it was taken here by Judah and Simeon, partly out of love for their brother Dan, and partly to secure their new conquests, and other adjoining territories, from such potent neighbours.