Hebrews 12:17 - Matthew Poole's English Annotations on the Holy Bible

For ye know how that afterward, when he would have inherited the blessing, he was rejected: as Esau's sin was, such was his penalty; for they knew, and were well acquainted with this in Moses's history of him, that after he had despised his birthright, and sold it, being at man's estate, Genesis 27:1-46, and was desirous to inherit that blessing, he was rejected by his father, as well as by God, and could not obtain it, being unalterably settled on Jacob by both. He found no place of repentance, as to the giving it, with God, who gave it, and would not alter it, Romans 11:29; nor with his father, who did not repent of giving it to Jacob, but confirmed it, Genesis 27:33,40 Genesis 28:1,3,4. Though he sought it carefully with tears; and this, although he sought the blessing from his father with cries and tears, Genesis 27:34,38. How therefore should these Hebrews, knowing all this, root out such a root springing up in themselves, or others, that they might not be guilty of such sin; lest having despised God's blessing for their own ease, honours, or profits in this world, when they may desire to seek with tears the blessing of the eternal inheritance from God, he should irreversibly reject them. See Matthew 7:22,23.