Jamieson, Fausset and Brown on Romans 9:25

25. As he saith also in Osee--"Hosea."

I will call them my people, which were not my people; and her beloved, which was not beloved--quoted, though not quite to the letter, from Ho 2:23, a passage relating immediately, not to the heathen, but to the kingdom of the ten tribes; but since they had sunk to the level of the heathen, who were "not God's people," and in that sense "not beloved," the apostle legitimately applies it to the heathen, as "aliens from the commonwealth of Israel and strangers to the covenants of promise" (so 1Pe 2:10).