Romans 9:24-26 (NASB)
even us, whom He also called, not from among Jews only, but also from among Gentiles. As He says also in Hosea, "I will call those who were not My people, 'My people,' And her who was not beloved, 'beloved.'" Romans 9 "And it shall be that in the place where it was said to them, 'you are not My people,' There they shall be called sons of the living God."
This is the reference as quoted by Paul in Romans
Hosea 1:9-10 (NASB)
And the Lord said, "Name him Lo-ammi, for you are not My people and I am not your God." Yet the number of the sons of Israel Will be like the sand of the sea, Which cannot be measured or numbered; And in the place Where it is said to them, "You are not My people," It will be said to them, "You are the sons of the living God."
Hosea 2:23 (NASB)
23"I will sow her for Myself in the land. I will also have compassion on her who had not obtained compassion, And I will say to those who were not My people, 'You are My people!' And they will say, 'You are my God!'"
Paul quotes Hosea as also referring to the Gentiles in his letter to the church at Rome,but it seems Hosea was only addressing the Jewish nation.
Does Hosea refer to the Gentiles at all?