Concise Bible Dictionary:
Plain and city on the east of the Jordan. It fell to the lot of Reuben, but was possessed at times both by the Amorites and the Moabites (Num. 21:30; Josh. 13:9,16; 1 Chron. 19:7; Isa. 15:2). Identified with Madeba, 31° 43' N, 35, 47' E.
Potts’ Bible Proper Names:
Water of peace, or quiet:― town in Reuben, E. of Dead Sea, Num. 21:30. {Aqua quietis}