Judges 20:22

Trusting in their strength. The Lord suffered them to be overthrown, and many of them to be slain, though their cause was just; partly in punishment of the idolatry which they exercised or tolerated in the tribe of Dan, and elsewhere: and partly because they trusted in their own strength: and therefore, though he bid them fight, he would not give them the victory, till they were thoroughly humbled, and had learned to trust in him alone. (Challoner) --- God's thoughts are often different from ours; and he frequently delays to crown with success the most holy enterprises, that man may learn to be more humble, and to trust wholly in his mercy. (Calmet)