en_tn/jos/17/14.md

the descendants of Joseph

This refers to the tribes of Ephraim and Manasseh. (See: rc://en/ta/man/jit/figs-explicit)

Why have you given us only one ... Yahweh has blessed us?

The people of the tribes of Ephraim and Manasseh ask this question to emphasize that Joshua should have assigned to them more land. Alternate translation: "You should have given us more than one ... Yahweh has blessed us." (See: rc://en/ta/man/jit/figs-rquestion)

one assignment of land and one portion for an inheritance

These two phrases mean basically the same thing. In the second, the land is spoken of as if it were an inheritance that the people received as a permanent possession. Alternate translation: "one assignment of land as our inheritance" (See: rc://en/ta/man/jit/figs-doublet and rc://en/ta/man/jit/figs-metaphor)

portion

part

people great in number

"many people"