The first part. — The first territory conquered by Moses was distributed between Reuben and Gad, and the half tribe of Manasseh.
A portion of the lawgiver is interpreted by Rashi as the field of the “burial-place” of the lawgiver. But this can hardly have been in the mind of Moses.
He came with the heads of the people. — The Gadites with their companion tribes passed over Jordan to the conquest of Canaan by Moses’ order.