Genesis 15:4

And, behold, the word of the Lord came unto him, saying, This shall not be thine heir; but he that shall come forth out of thine own bowels shall be thine heir.

Cross-references

Genesis 17:16 specifies what 15:4 promised broadly: God names Sarah as the mother and promises a son through her specifically.

Genesis 21:12 confirms the principle God stated here: the covenant heir must come through the biological line, not a servant's son.

In 2 Samuel 7:12, God repeats this same promise language — a son 'from your own flesh and blood' — now applied to David's dynasty, echoing the Abrahamic heir promise.

Isaiah 51:2 Allusion

Isaiah 51:2 explicitly recalls Abraham — called alone yet blessed and multiplied — pointing back to God's heir and descendants promise.