Verses 15-16 And God said to Abraham, As for Sarai your wife, you shall not call her name Sarai, but Sarah shall her name be. And I will bless her, and give you a son also of her: yea, I will bless her, and she shall be a mother of nations; kings of people shall be of her.
God changes Sarai’s name to Sarah.
Sarai means “princess”
Sarah means “mother of nations”
This is the first time that God has specifically said that Sarah will have a son. Until now, God has only said that Abraham would have a son.
Verses 17-19 Then Abraham fell on his face, and laughed, and said in his heart, Shall a child be born to him that is a hundred years old? and shall Sarah, that is ninety years old, bear? And Abraham said to God, O that Ishmael might live before you!
What is Abraham’s response when God tells him that he and Sarah will have a child? Vs. 17 He laughed. We often hear that Sarah laughed, but we don’t often hear that Abraham laughed also.
What was Abraham saying in verse 18? Verse 18 – Abraham loves Ishmael. Ishmael is 13 years old and Abraham has raised him as his only son. He said if only you could use Ishmael to fulfill your promises (to establish your covenant), Sarah and I wouldn’t need to have a child. Another possible meaning: Josephus says that Abraham was actually concerned about whether Ishmael would live or not. God assured Abraham that Ishmael would indeed live and become a great nation.
Vs. 19 God restates that Sarah will have a son. He adds that the son will be called Isaac. It is through Isaac that the covenant will be established and with his seed.
Skip vs. 20 – Discussed with Ishmael
Verse 21 But my covenant will I establish with Isaac, which Sarah shall bear unto you at this set time in the next year.
Sarah will have Isaac at this set time next year. What do you think that means? God knows everything that will happen. He is omniscient. His timing can be truly amazing. You have heard stories and maybe even experienced God’s provision in perfect timing. We should not be surprised that he is promising the timing of the birth of Isaac. God may be speaking generally of the month, week, or day; however, He may be speaking of the specific hour, minute, or even the very second. I think this means on this day next year and maybe even at this hour, Sarah will have the child, maybe even this very minute next year.
Read Genesis 18:9-15
This incident is separate from when Abraham laughs and the Lord says Sarah will have Isaac at this set time next year. I think this visit from the Lord is approximately 3 months later. The reason I think this is because “ at this set time next year” and then in vs. 10 and 14 here the Lord says, at the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son. I’m thinking this is talking about the conception. If the Lord will return for the conception, this visit would be approximately three months later.
Verse 15 – Sarah did not lie. She did not laugh out loud. She only laughed within her heart. Like a patient parent who knows the truth, God says No, you did laugh. God knows not only Sarah’s actions but also her heart.
Read Genesis 21:1-7
God’s word is true. He keeps His promises. Isaac is born.
The name Isaac means “laughter.” Both Abraham and Sarah laughed when they thought of the apparent impossibility of this birth. Then in chapter 21 verse 6 Sarah says God has made me to laugh so that all who hear will laugh with me (a laugh of joyful wonder).
Sarah dies and is buried. How old was Sarah when she died?
Vs. 1 – 127 years old
Isaac was 36, Abraham was 137
Consider the courtesy displayed between Abraham and Ephron as they bargain for the cave where Sarah was buried.
Who else was buried where Sarah was buried?
Abraham, Isaac, Rebekah, Leah, Jacob
Sarah is given to us as an example. What did Sarah do that was exemplary?
Obeyed her husband
Sarah is also an example of faith
Sarah is the only woman in the “Hall of Faith”
Through faith she received strength to conceive seed
I think of times when Jesus healed the sick. “Your faith has made you whole.” “Let it be done according to your faith.”
Paul expounds the narrative of Ishmael and Isaac allegorically. Hagar represents the old covenant and Sarah, the new. The rivalry between Ishmael and Isaac foreshadows the conflict in the early church between those who cling to the ordinances of the Law (which must pass away) and those who realize that through the grace of Christ there is freedom from the law.