Numbers 34:14

For the tribe of the children of Reuben, according to the
house of their fathers
That tribe, and all the families belonging to it:

have received their inheritance, and half the tribe of Manasseh
have received their inheritance; that is, it was agreed they should have it on condition of their going along with the other tribes over Jordan into the land of Canaan, and assist them in the conquest of it, ( Numbers 32:1-42 ) .