Galatians 4:22-24

²²For it is written that Abraham had two sons, one by the handmaid, and one by the free woman. ²³However, the son by the handmaid was born according to the flesh, but the son by the free woman was born through promise. ²⁴These things contain an allegory, for these are two covenants. One is from Mount Sinai, bearing children to bondage, which is Hagar.