Genesis 18:10-14

10The Lord said, “I will surely return to you aabout this time next year, and bSarah your wife shall have a son.” And Sarah was listening at the tent door behind him. 11Now cAbraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah. 12 dSo Sarah laughed to herself, saying, eAfter I am worn out, and fmy lord is old, shall I have pleasure?” 13The Lord said to Abraham, “Why did Sarah laugh and say, ‘Shall I indeed bear a child, now that I am old?’ 14 gIs anything too hard
Or wonderful
for the Lord? iAt the appointed time I will return to you, about this time next year, and Sarah shall have a son.”

Genesis 25:21-23

21And Isaac prayed to the Lord for his wife, because she was barren. And jthe Lord granted his prayer, and Rebekah his wife conceived. 22The children struggled together within her, and she said, “If it is thus, why is this happening to me?”
Or  why do I live?
So she went lto inquire of the Lord.
23And the Lord said to her,

mTwo nations are in your womb,
and two peoples from within you
Or  from birth
shall be divided;
othe one shall be stronger than the other,
pthe older shall serve the younger.”
Copyright information for ESV