Acts 7:8 And he gave him the covenant of circumcision: and so Abraham begat Isaac, and circumcised him the eighth day; and Isaac begat Jacob; and Jacob begat the twelve patriarchs.

Galatians 4:22 For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman.

Hebrews 11:11 Through faith also Sara herself received strength to conceive seed, and was delivered of a child when she was past age, because she judged him faithful who had promised.

Genesis 17:21 But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.

Genesis 18:10 And he said, I will certainly return unto thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him.

Genesis 18:14 Is any thing too hard for the LORD? At the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son.

Romans 9:9 For this is the word of promise, At this time will I come, and Sara shall have a son.