Genesis 18:10
10 The Lord said, “I will surely return to you uabout this time next year, and vSarah your wife shall have a son.” And Sarah was listening at the tent door behind him.
Genesis 21:2
2 And Sarah mconceived and bore Abraham a son in his old age nat the time of which God had spoken to him.
Galatians 4:23
23 But gthe son of the slave was born according to the flesh, while hthe son of the free woman was born through promise.
Galatians 4:28
28 Now you,1 brothers, mlike Isaac, nare children of promise.