en_tn_lite_do_not_use/jos/13/23.md

this is their boundary

The Jordan River was the western border of the land that the tribe of Reuben received.

This was the inheritance of the tribe of Reuben

The land that Moses assigned to the tribe of Reuben is spoken of as if it were an inheritance that the tribe of Reuben received as a permanent possession. (See: rc://en/ta/man/jit/figs-metaphor)

given to each of their clans

This can be stated in active form. Alternate translation: "that Moses gave to each of their clans" (See: rc://en/ta/man/jit/figs-activepassive)