Jos Joshua, chapter Book of Joshua, chapter 13
And all the towns of the plain, and kol mamlechot Shichon Melech HaEmori, who reigned in Cheshbon, whom Moshe conquered with the nasiim of Midyan, Evi, and Rekem, and Tzur, and Chur, and Reva, which were vassal princes under Sichon, dwelling in HaAretz. Num 31:8