So there went up thither of the people about three thousand men: and they fled before the men of Ai.

Wesley's Notes

7:4 They fled - Not having courage to strike a stroke, which was a plain evidence that God had forsaken then; and an useful instruction, to shew them what they were when God left them: and that it was God, not their own valour, that gave the Canaanites into their hands.

Jamieson-Fausset-Brown Bible Commentary

4, 5. they fled before the men of Ai-An unexpected resistance, and the loss of thirty-six of their number diffused a panic, which ended in an ignominious rout.

Matthew Henry's Concise Commentary

7:1-5 Achan took some of the spoil of Jericho. The love of the world is that root of bitterness, which of all others is most hardly rooted up. We should take heed of sin ourselves, lest by it many be defiled or disquieted, Heb 12:15; and take heed of having fellowship with sinners, lest we share their guilt. It concerns us to watch over one another to prevent sin, because others' sins may be to our damage. The easy conquest of Jericho excited contempt of the enemy, and a disposition to expect the Lord to do all for them without their using proper means. Thus men abuse the doctrines of Divine grace, and the promises of God, into excuses for their own sloth and self-indulgence. We are to work out our own salvation, though it is God that works in us. It was a dear victory to the Canaanites, whereby Israel was awakened and reformed, and reconciled to their God, and the people of Canaan hardened to their own ruin.