Pseudo Jonathan Genesis 21:9

And the Lord remembered Sarah according to that which He had said to her; and the Lord wrought a miracle for Sarah like to that for which Abraham had spoken in prayer for Abimelek. And she conceived, and Sarah bare to Abraham a son, who was like to himself in his age, at the time of which the Lord had spoken to him. And Abraham called the name of his son whom Sarah had borne him Izhak. And Abraham circumcised Izhak his son, when the son of eight days, as the Lord had commanded him. And Abraham was the son of an hundred years when Izhak his son was born to him. And Sarah said, The Lord hath done wondrously for me; all who hear will wonder at me. And she said, How faithful was the messenger who announced to Abraham, and said, Sarah will nurse children, for she shall bring forth a son in her old age! And the child grew and was weaned. And Abraham made a great feast on the day when Izhak was weaned. And Sarah observed the son of Hagar the Mizreitha, whom she bare to Abraham, mocking with a strange worship, and bowing to the Lord. And she said to Abraham, Cast out this handmaid and her son: for it is not possible for the son of this handmaid to inherit with my son; and he to make war with Izhak. And the thing was very evil in Abraham's eyes, on account of Ishmael his son, who would practise a strange worship.

Date: 300-1200 C.E.
* Dates are based on scholarly estimates
New Testament

Galatians 4:29

21 Tell me, you who want to be under the law, do you not understand the law? 22 For it is written that Abraham had two sons, one by the slave woman and the other by the free woman. 23 But one, the son by the slave woman, was born by natural descent, while the other, the son by the free woman, was born through the promise. 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. 25 Now Hagar represents 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, and she is our mother. 27 For it is written:“Rejoice, O barren woman who does not bear children; break forth and shout, you who have no birth pains,because the children of the desolate woman are more numerousthan those of the woman who has a husband.” 28 But you, brothers and sisters, are children of the promise like Isaac. 29 But just as at that time the one born by natural descent persecuted the one born according to the Spirit, so it is now. 30 But what does the scripture say? “Throw out the slave woman and her son, for the son of the slave woman will not share the inheritance with the son” of the free woman. 31 Therefore, brothers and sisters, we are not children of the slave woman but of the free woman.

Date: 54-55 C.E.
* Dates are based on scholarly estimates