Divrey Hayamim Bais 20:23

23 For the Bnei Ammon and Moav stood up against the inhabitants of Mt Seir, utterly to slay and destroy them. And when they had made an end of the inhabitants of Seir, every one helped to destroy another.

Divrey Hayamim Bais 20:23 Meaning and Commentary

2 Chronicles 20:23

For the children of Ammon and Moab stood up against the
inhabitants of Mount Seir
Supposing that they had acted a treacherous part by them, and took on the side of their enemies: utterly to slay and destroy them;
as they did: and when they had made an end of the inhabitants of Seir;
so that there were none left of them: everyone helped to destroy one another;
in their confusion mistook one another, either for Edomites or Jews, like the Midianites in the times of Gideon.

Divrey Hayamim Bais 20:23 In-Context

21 And when he had consulted with HaAm, he appointed meshorarim (singers) unto Hashem, and that should praise the hadrat kodesh, as they went out before the army, and to say, Hodu L’Adonoi ki l’olam chasdo (Give thanks to Hashem, for His mercy endureth forever).

22 And when they began with rinnah and tehillah, Hashem set me’arevim (ambushers) against the Bnei Ammon, Moav, and Mt Seir, which were come against Yehudah, and they were struck down.

23 For the Bnei Ammon and Moav stood up against the inhabitants of Mt Seir, utterly to slay and destroy them. And when they had made an end of the inhabitants of Seir, every one helped to destroy another.

24 And when Yehudah came toward the mitzpeh (guard tower) in the midbar, they looked toward the multitude, and, hinei, they were pegarim (corpses) fallen on the ground, and there was no escapee.

25 And when Yehoshaphat and his people came to carry off the plunder of them, they found among them in abundance both property with the pegarim, and articles of value, which they stripped off for themselves, more than they could carry away, and they were yamim shelosha in gathering of the plunder, it was so much.