Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!” Now Sarah was behind him, listening at the entrance to the tent.
And the LORD asked Abraham, “Why did Sarah laugh and say, ‘Can I really bear a child when I am old?’ Is anything too difficult for the LORD? At the appointed time I will return to you—in about a year—and Sarah will have a son.”
And the angel of the LORD called to Abraham from heaven a second time, saying, “By Myself I have sworn, declares the LORD, that because you have done this and have not withheld your only son,
And Elisha declared, “At this time next year, you will hold a son in your arms.” “No, my lord,” she said. “Do not lie to your maidservant, O man of God.” But the woman did conceive, and at that time the next year she gave birth to a son, just as Elisha had told her.
And I will bless her and will surely give you a son by her. I will bless her, and she will be the mother of nations; kings of peoples will descend from her.” ... But God replied, “Your wife Sarah will indeed bear you a son, and you are to name him Isaac. I will establish My covenant with him as an everlasting covenant for his descendants after him. ... But I will establish My covenant with Isaac, whom Sarah will bear to you at this time next year.”
The angel of the LORD appeared to the woman and said to her, “It is true that you are barren and have no children; but you will conceive and give birth to a son. Now please be careful not to drink wine or strong drink, and not to eat anything unclean. For behold, you will conceive and give birth to a son. And no razor shall come over his head, because the boy will be a Nazirite to God from the womb, and he will begin the deliverance of Israel from the hand of the Philistines.”
But the angel said to him, “Do not be afraid, Zechariah, because your prayer has been heard. Your wife Elizabeth will bear you a son, and you are to give him the name John.
So it is not the children of the flesh who are God’s children, but it is the children of the promise who are regarded as offspring. For this is what the promise stated: “At the appointed time I will return, and Sarah will have a son.”
His son by the slave woman was born according to the flesh, but his son by the free woman was born through the promise. ... Now you, brothers, like Isaac, are children of promise.