Numbers 32:29; Numbers 32:33

29 And Moses said to them, "If the people of Gad and the people of Reuben, every man who is armed to battle before the LORD, will pass with you over the Jordan and the land shall be subdued before you, then you shall give them the land of Gilead for a possession.

33 And Moses gave to them, to the people of Gad and to the people of Reuben and to the half-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 and its cities with their territories, the cities of the land throughout the country.