This refers to the east side of the Jordan River. Later most of the Israelites would live west of the Jordan, so they called the east side "beyond the Jordan." But at this time they were all still on the east side. AT: "east of the Jordan River" (See: [[rc://en/ta/man/translate/figs-idiom]])
# given your brothers rest
This refers to Israel defeating all their enemies residing in Canaan that they were to conquer. (See: [[rc://en/ta/man/translate/figs-idiom]])
# you will ... possess it
This refers to living out their life on the land in peace.