Here in Judah. — This does not imply that Keilah was out of the territory of Judah, but simply that the district in the neighbourhood round Keilah was at that time under Philistine domination. The open country in times of Philistine supremacy first fell under their control; their strong places, like Keilah, would resist for a much longer period.
Related Commentaries of 1 Samuel 23:3
1 Samuel 23:3
3 And David's men said unto him, Behold, we be afraid here in Judah: how much more then if we come to Keilah against the armies of the Philistines?