Psalms 82:8
Arise, O God, judge the Earth, for you shall inherit all the nations!
Scripturally, a Gentile was nothing more than a member of one of the 70 nations of Genesis 10 that were allotted to the watchers in Deuteronomy 32.
The prophets predicted that when Messiah came, he would not only unite the houses of Judah and Israel, but he would bring the Gentile nations, previously cut off from his covenant, into his new covenant kingdom.