en_tn_condensed/deu/03/20.md

Yahweh gives rest to your brothers

The writer speaks as if the ability to rest were a physical object that could be given as a gift. The word "rest" is also a metaphor for peaceful life in which there is no war. Alternate translation: "Yahweh allows your brothers to rest" or "Yahweh allows your brothers to stop fighting wars and live peacefully" (See: rc://en/ta/man/jit/figs-metaphor)

beyond the Jordan

This refers to the land across the Jordan River, to the east of Israel. Moses was east of the Jordan when he said this. See how you translated these words in Deuteronomy 1:1. Alternate translation: "east of the Jordan River"

then will you return

Moses is emphasizing that the other tribes must possess their land before Yahweh will permit these three tribes to possess their land. "only then are you to return."