This phrase is found repeated not only at the end of Reuben’s division, but also for Gad, Manasseh, and all the other tribes. It is meant to show how God’s people were adhering to the provisions made in the law given to Moses. Leviticus 25:1–55 mentions that land is to remain in each clan which is also obligated to redeem land for their families (Leviticus 25:23–28, Leviticus 25:41, Leviticus 25:49). Land was meant to remain in the hands of each clan.1
15 And Moses gave an inheritance to the tribe of the people of Reuben according to their clans.