Genesis 21:5 - Exposition

And Abraham was an hundred years old (cf. Genesis 17:1 , Genesis 17:17 ), when his son Isaac was born unto him . Literally, at the time of bearing to him (ἐν τῷ τεκεῖν) Isaac . Thus Abraham had waited twenty-five years for the fulfillment of the promise—a remarkable instance of faith and patience ( Romans 4:20 ), as Isaac's birth was a signal display of Divine power ( Romans 4:17 ; Hebrews 11:12 ). Whether Isaac was born at Gerar or at Beersheba cannot with certitude be inferred.