en_tn/deu/17/15.md

someone from among your brothers

"one of your fellow Israelites"

a foreigner, who is not your brother, over yourself

Both of these phrases mean the same thing. They both refer to a person who is not an Israelite. Yahweh is emphasizing that the people of Israel should not let a foreigner rule over them. Alternate translation: "a foreigner over yourself" or "a non-Israelite over yourself" (See: rc://en/ta/man/jit/figs-doublet)