Isaiah 56:8

With an unusually strong declaration (cf. Isaiah 1:24), sovereign Yahweh affirmed that He would gather many other Gentiles to Himself along with the Israelites (cf. Isaiah 19:25; Isaiah 49:6-7; Isaiah 51:5; Isaiah 55:5; John 10:16). He would not save only Israelites, but Gentiles as well. The new revelation, or mystery, concerning the relationship of Jews and Gentiles in the church (Ephesians 2-3), was not that God would save Gentiles as well as Jews. It was that in the church He would deal with Jews and Gentiles on the same basis. Jews would have no advantage over Gentiles as they did previously. Now both types of people could come into relationship with God directly through faith in Christ. Formerly Gentiles came into relationship with God indirectly-through Israel-through faith in Yahweh. The Lord was not referring to the Babylonian exile or to geographical dispersal, but to those scattered from Himself.