How did God answer Abraham's request that Ishmael be the heir?
God refuted Abraham’s request and declined to make Ishmael the heir. He told Abraham that Sarah, his wife—not the slave girl—would bear him a son to be named Isaac, and God would establish His everlasting covenant with Isaac, not Ishmael.
Les explains that in Genesis 17 Abraham again operates in the energy of the flesh and asks, “O that Ishmael might live before thee,” essentially asking why Ishmael could not fulfill God’s promises. Les teaches that God refutes him in verse 19, saying Sarah thy wife, not the slave girl, shall bear thee a son indeed; his name is to be Isaac. God says, “I will establish my covenant with him for an everlasting covenant,” showing that whenever there is an “I will” from God in Scripture, it is a promise. Thus Isaac, not Ishmael, becomes the promised son.
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.
More Questions
Did the Abrahamic covenant continue through Isaac or through Ishmael?
The Abrahamic covenant did not pass through Ishmael; God continued it through Isaac and Isaac's descendants.