Genesis 18:9-15, 21:1-7

⁹ They said to him, “Where is Sarah your wife?” And he said, “She is in the tent.” ¹⁰ The Lord said, “I will surely return to you about this time next year, and Sarah your wife shall have a son.” And Sarah was listening at the tent door behind him. ¹¹ Now Abraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah. ¹² So Sarah laughed to herself, saying, “After I am worn out, and my lord is old, shall I have pleasure?” ¹³ The Lord said to Abraham, “Why did Sarah laugh and say, ‘Shall I indeed bear a child, now that I am old?’ ¹⁴ Is anything too hard for the Lord? At the appointed time I will return to you, about this time next year, and Sarah shall have a son.” ¹⁵ But Sarah denied it, saying, “I did not laugh,” for she was afraid. He said, “No, but you did laugh.”

21:1 The Lord visited Sarah as he had said, and the Lord did to Sarah as he had promised. ² And Sarah conceived and bore Abraham a son in his old age at the time of which God had spoken to him. ³ Abraham called the name of his son who was born to him, whom Sarah bore him, Isaac. ⁴ And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. ⁵ Abraham was a hundred years old when his son Isaac was born to him. ⁶ And Sarah said, “God has made laughter for me; everyone who hears will laugh over me.” ⁷ And she said, “Who would have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.”