As He says also in Hosea:

“I will call them My people, who were not My people,
And her beloved, who was not beloved.”
 “And it shall come to pass in the place where it was said to them,
‘You are not My people,’
There they shall be called sons of the living God.” (Romans 9:25-26 NKJV)

ROMANS 9 IN ITS ENTIRETY.