BLB(i)
22 For it has been written that Abraham had two sons, one of the slave woman and one of the free.
23 But indeed, the one of the slave woman has been born according to flesh, but the one of the free, through the promise,
24 which things are allegorized, for these are two covenants: one indeed from Mount Sinai, begetting unto slavery, which is Hagar.
25 Now Hagar is Mount Sinai in Arabia and corresponds to the present Jerusalem, for she is in slavery with her children.
26 But the Jerusalem above is free, who is our mother.