Galatians 4:22

For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman.

Surrounding context

4:21 Tell me, you who desire to be under the law, do you not hear the law?

4:22 For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman.

4:23 But he who was of the bondwoman was born according to the flesh, and he of the freewoman through promise,