“And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.”
My Notes
What Does Genesis 17:19 Mean?
God makes the promise specific: Sarah — ninety-year-old, barren Sarah — will bear a son. His name will be Isaac (Yitschaq — he laughs). And the everlasting covenant will be established through him, not through Ishmael (whom Abraham suggested in verse 18).
The naming before the birth is significant: God names the child before the child exists. The identity precedes the existence. Isaac is named, covenanted, and purposed before he's conceived. God isn't reacting to events. He's announcing them.
"An everlasting covenant" (berit olam) — the same phrase used for the rainbow covenant (9:16) and the circumcision covenant (17:7). The covenant with Isaac isn't temporary or conditional. It's permanent. And it flows through him to "his seed after him" — a line that extends to Christ.
Reflection Questions
- 1.What 'impossible son' is God trying to produce through your barren situation?
- 2.Does God's choice of the impossible path (Isaac, not Ishmael) encourage you about the impractical thing He might be doing in your life?
- 3.How does the name 'Laughter' (Isaac) capture both doubt and delight?
- 4.What does 'everlasting covenant' through the impossible child mean for how God works in general?
Devotional
Sarah will have a son. You'll name him Laughter. And the everlasting covenant goes through him.
God names the baby before he's born. Isaac — he laughs — named after Abraham's laugh of disbelief (verse 17) and Sarah's laugh of joy (18:12). The name captures both: the impossibility that made them laugh and the fulfillment that will make them weep with joy. The child carries the laughter of his parents' doubt and his parents' delight in one name.
The covenant is everlasting. Not through Ishmael — Abraham tried that (verse 18: "O that Ishmael might live before thee!"). God honored Ishmael with a blessing (verse 20). But the covenant goes through the impossible son. The child of the barren wife. The one who shouldn't exist.
God consistently chooses the impossible path. Not the practical one (Ishmael was already born and healthy). Not the obvious one (Abraham had a son who could carry things forward). The impossible one. The ninety-year-old woman. The barren womb. The laugh that becomes a name.
Why? Because the covenant has to be unmistakably God's work. If Isaac came through natural means, the credit could go elsewhere. But a child born to a ninety-year-old barren woman? That's God's signature. Unmistakable. Undeniable. And very, very funny.
The everlasting covenant rides on laughter. On impossibility. On a baby who shouldn't exist, carrying a promise that will never expire.
Commentary
Trusted original commentary from respected historical Bible scholars and theologians.
And God said, Sarah thy wife shall bear thee a son indeed,.... This is repeated for the confirmation of it, and thus…
- The Sealing of the Covenant 1. שׁדי shaday, Shaddai, “Irresistible, able to destroy, and by inference to make,…
Here is, I. The promise made to Abraham of a son by Sarai, that son in whom the promise made to him should be fulfilled,…
Sarah thy wife God's answer in this verse is made to the utterance of Abraham's heart (Gen 17:17), and not of his lips…
Cross References
Related passages throughout Scripture