Galatians 3:16

3:16 Now the promises were spoken to Abraham and to his descendant. Scripture does not say, “and to the descendants,” referring to many, but “and to your descendant,” referring to one, who is Christ.

Galatians 4:27

4:27 For it is written:

“Rejoice, O barren woman who does not bear children;

break forth and shout, you who have no birth pains,

because the children of the desolate woman are more numerous

than those of the woman who has a husband.”