I commanded you: as the context shows, Moses is speaking to the three tribes that settled east of the Jordan. Contemporary English Version makes this clear with “At the same time I told the men of Reuben, Gad, and half of Manasseh.”

The LORD your God: again, if the second person plural your makes it appear that Yahweh is not the God of Moses, the inclusive form of the first person plural should be used, namely, “The LORD our [inclusive] God.” For a comment on LORD, or “Yahweh,” see 1.3.

This land: that is, the land east of the Jordan River (compare Good News Translation).

All your men of valor shall pass over armed before your brethren the people of Israel: the meaning is that the fighting men or soldiers of the three tribes east of the Jordan were to cross the Jordan River to the west side ahead of the fighting men from the other tribes and help them conquer the territory on the west side. When the conquest was completed, they were to return to their homes east of the Jordan. See Num 32.16-22. Armed suggests the act of “arming” them. Good News Translation has “Now arm your fighting men”; or we may say “Now give weapons to your soldiers.”

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .