Moses speaks a poetic song to the people of Israel. As he speaks to the Israelites, he talks about them as if they were someone else and as if they were one man. (See: [[rc://en/ta/man/translate/figs-parallelism]])
These two phrases means basically the same thing and and can be combined. Alternate translation: "The descendants of Jacob are Yahweh's inheritance" (See: [[rc://en/ta/man/translate/figs-parallelism]])