Bereshis 21:1-3

Orthodox Jewish Bible

21 And Hashem visited Sarah as He had said, and Hashem did unto Sarah just as He had spoken.

² For Sarah conceived, and bore Avraham ben in his old age, at the mo’ed (set time) of which Elohim had given promise unto him.

³ And Avraham called the shem of bno that was born unto him, whom Sarah bore to him, Yitzchak.