Deuteronomy 3:16-20

16and to the Reubenites and the Gadites I gave the territory from Gilead as far as the Valley of the Arnon, with the middle of the valley as a border, as far over as the river Jabbok, the border of the Ammonites; 17the Arabah also, with the Jordan as the border, from Chinnereth as far as the Sea of the Arabah, the Salt Sea, under the slopes of Pisgah on the east. 18“And I commanded you at that time, saying, ‘The LORD your God has given you this land to possess. All your men of valor shall cross over armed before your brothers, the people of Israel. 19Only your wives, your little ones, and your livestock (I know that you have much livestock) shall remain in the cities that I have given you, 20until the LORD gives rest to your brothers, as to you, and they also occupy the land that the LORD your God gives them beyond the Jordan. Then each of you may return to his possession which I have given you.’