But could not drive out the inhabitants, &c.— But proceeded not to drive out, &c. Jun. Tremel. Wat. This version gives us the true sense of the passage. We are not to suppose that chariots of iron rendered the inhabitants of the valley invincible to a people aided and protected by Almighty God; but only that these tribes, content with their former victories, and terrified at the formidable appearance of the enemy, wanted confidence in the Lord, and dared not to attack the Philistines; insomuch, that, being unworthy of God's succour, they were left to themselves, to their false policy and shameful timidity: and hence, perhaps, they abandoned Gaza, Askelon, and Ekron, which they had before taken. See ch. Judges 3:3.
Note; (1.) They who do the work of the Lord unfaithfully will surely suffer for it. (2.) A favourable opportunity neglected can very rarely be recovered. (3.) Unbelief of God's promises is the cause of all our complaints.