Albert Barnes Commentary 2 Chronicles 20:10

"And now, behold, the children of Ammon and Moab and mount Seir, whom thou wouldest not let Israel invade, when they came out of the land of Egypt, but they turned aside from them, and destroyed them not;" — 2 Chronicles 20:10 (ASV)

The Maonites of 2 Chronicles 20:1 are also called the “children” or inhabitants “of Mount Seir” in 2 Chronicles 20:22–23. From this, we can gather that they were a tribe of Edomites, probably the inhabitants of a city named Maon (now Ma’an) on the eastern side of the Wadi el-Arabah.