He said to them, Follow after me; for Yahweh has delivered your enemies the Moabites into your hand. They went down after him, and took the fords of the Jordan against the Moabites, and didn't allow a man to pass over.
Judges 3:29 is difficult to interpret for two reasons. First, the word translated "thousand" can also mean "military unit" (cf. Judges 20:10). Second, it is not clear whether the Israelites killed these Moabites as they tried to cross the Jordan on this occasion. Perhaps this was the total Moabite force that the Israelites killed in their war with Moab. In either case this was a great victory for Israel.