Targum zu Bamidbar 21:15

And the effusion of the streams of their blood flowed to the habitations of Lechaiath, which were, however, delivered from this destruction, because they had not been in their counsels; and, behold, it was unto the confine of Moab.

When the children of Israel were passing through the vale of Arnona, the Moabites were hidden in the caverns of the valley, saying: When the Beni Israel are coming through, we will go forth to prevent them, and will slay them. But the Lord of all the world, the Lord, who knew what was in their hearts, for before Him that which is within the reins is manifest, the Lord signed to the mountains, and their heads here and there were brought together, and the chiefs of their mighty ones were crushed, and the valleys were overflowed with the blood of the slain. But Israel walked above upon on the top of the hills, and knew not the miracle and mighty act which the Lord was doing for them in the valley of Arnon. But Lechaiath, the city which took no part in their counsel, was delivered from them; and, behold, it is by the confines of the Moabites.