Great stones, i.e. hailstones of extraordinary greatness and hardness, cast down with that certainty as to hit the Canaanites, and not their pursuers the Israelites, and with that force as to kill them. Josephus affirms that thunder and lightning were mixed with the hail, which may seem probable from Habakkuk 3:11.
Related Commentaries of Joshua 10:11
Joshua 10:11
11 And it came to pass, as they fled from before Israel, and were in the going down to Bethhoron, that the LORD cast down great stones from heaven upon them unto Azekah, and they died: they were more which died with hailstones than they whom the children of Israel slew with the sword.