Genesis 21:2-5

The Birth of Isaac

² And Sarah _m conceived and bore Abraham a son in his old age _n 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, _o Isaac. ₁ ⁴ And Abraham _p circumcised his son Isaac when he was eight days old, _q as God had commanded him. ⁵ _r Abraham was a hundred years old when his son Isaac was born to him.

1. Cross References
   Hebrews 11:11
   By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised.
   Galatians 4:22
   For it is written that Abraham had two sons, one by a slave woman and one by a free woman.
   
2. Cross References
   Genesis 17:21
   But I will establish my covenant with Isaac, whom Sarah shall bear to you at this time next year.
   
3. Cross References
   Genesis 17:19
   God said, "No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him.
   
4. Cross References
   Acts 7:8
   And he gave him the covenant of circumcision. And so Abraham became the father of Isaac, and circumcised him on the eighth day, and Isaac became the father of Jacob, and Jacob of the twelve patriarchs.
   
5. Cross References
   Genesis 17:10
   This is my covenant, which you shall keep, between me and you and your offspring after you: Every male among you shall be circumcised.
   Genesis 17:12
   He who is eight days old among you shall be circumcised. Every male throughout your generations, whether born in your house or bought with your money from any foreigner who is not of your offspring.
   
6. Cross References
   Genesis 17:1
   When Abram was ninety-nine years old the Lord appeared to Abram and said to him, "I am God Almighty; walk before me, and be blameless.
   Genesis 17:17
   Then Abraham fell on his face and laughed and said to himself, "Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?
   Romans 4:19
   He did not weaken in faith when he considered his own body, which was as good as dead ( since he was about a hundred years old), or when he considered the barrenness of Sarah's womb.