Albert Barnes Commentary Deuteronomy 3:10

"all the cities of the plain, and all Gilead, and all Bashan, unto Salecah and Edrei, cities of the kingdom of Og in Bashan." — Deuteronomy 3:10 (ASV)

Salchah - Compare Joshua 12:5; 1 Chronicles 5:11, where it is named as belonging to the tribe of Gad. It lies seven hours’ journey to the southeast of Bostra or Bozrah of Moab. As the eastern border city of the kingdom of Bashan it was no doubt strongly fortified.

Edrei - Compare Numbers 21:33 note.