Galatians 4:24-26
4:24 These things may be treated as an allegory, for these women represent two covenants. One is from Mount Sinai bearing children for slavery; this is Hagar.
4:25 Now Hagar represents Mount Sinai in Arabia and corresponds to the present Jerusalem, for she is in slavery with her children.
4:26 But the Jerusalem above is free, and she is our mother.