What does the Bible say about God's promise to Abraham?

In Genesis 17, God reaffirms His promise to Abraham, declaring that not only will he have a son, Isaac, but that Isaac will be the heir to God's everlasting covenant. This promise signifies that God's covenant is passed through Isaac and not Ishmael, highlighting God's sovereign choice in the unfolding of His redemptive plan. This act of confirming a promise serves as a demonstration of God's faithfulness and demonstrates how God can accomplish His purposes even against overwhelming earthly circumstances.