Galatians 4:24-25

24Now these facts are about to be used [by me] as an allegory [that is, I will illustrate by using them]: for these women can represent two covenants: one [covenant originated] from Mount Sinai [where the Law was given] that bears children [destined] for slavery; she is Hagar.

25Now Hagar is (represents) Mount Sinai in Arabia and she corresponds to the present Jerusalem, for she is in slavery with her children.