2 For Sarah conceived, and bore Abraham a son in his old age, at the set time of which God had spoken to him.
Genesis 21:2 Cross References - TKJU
Genesis 17:19
19 And God said, "Sarah your wife shall bear you a son indeed; and you shall call his name Isaac: And I will establish My covenant with him for an everlasting covenant, and with his seed after him.
Genesis 17:21
21 But I will establish My covenant with Isaac, which Sarah shall bear to you at this set time in the next year."
Genesis 18:10
10 And he said, "I will certainly return to you according to the time of life; and lo, Sarah your wife shall have a son." And Sarah heard it in the tent door, which was behind him.
Genesis 18:14
14 Is anything too hard for the LORD? At the time appointed I will return to you, according to the time of life, and Sarah shall have a son."
2 Kings 4:16-17
Luke 1:24-25
Luke 1:36
36 And behold, your cousin Elisabeth has also conceived a son in her old age: And this is the sixth month with her, who was called barren.
Acts 7:8
8 Then He gave him the covenant of circumcision: And so Abraham begot Isaac, and circumcised him on the eighth day; and Isaac begot Jacob; and Jacob begot the twelve patriarchs.
Romans 9:9
9 For this is the word of promise, "At this time I will come, and Sarah shall have a son."
Galatians 4:22
22 For it is written, that Abraham had two sons, the one by a bondwoman, the other by a freewoman.
Hebrews 11:11
11 Through faith Sarah herself also received strength to conceive seed, and was delivered of a child when she was past age, because she judged Him faithful who had promised.