Numbers 32:31-33

31Then the children of Gad and the children of Reuben answered, saying: “As the Lord has said to your servants, so we will do.

32We will cross over armed before the Lord into the land of Canaan, but the possession of our inheritance shall remain with us on this side of the Jordan.”

33So Moses gave to the children of Gad, to the children of Reuben, and to half the tribe of Manasseh the son of Joseph, the kingdom of Sihon king of the Amorites and the kingdom of Og king of Bashan, the land with its cities within the borders, the cities of the surrounding country.