Isaac's Irrevocable Blessing To Jacob
Isaac's blessing of Jacob, though obtained through deception, became irrevocable once pronounced—a reality that shaped both the patriarch's understanding and the theological interpretation of divine providence working through flawed human action. When Isaac realized he had blessed Jacob instead of Esau, he declared that the blessing could not be recalled: "I have blessed him—yes, and he will be blessed" (Genesis 27:33). This irrevocability was not merely Isaac's stubbornness but reflected his recognition that he had spoken prophetically under divine impulse [2].
The Nature of Patriarchal Blessing
The blessing Isaac gave was not simply a father's wish but a prophetic utterance "concerning things to come" [1]. Josephus describes Isaac as experiencing "a second afflatus" that enabled him to foretell future events for both Jacob and Esau, suggesting the blessing functioned as divinely inspired prediction rather than mere paternal preference [2]. This prophetic dimension meant Isaac understood himself as transmitting "the covenant deposited with himself to his son Jacob," acting not as a private person but under divine commission [5].
Confirmation and Ratification
The rabbinic tradition recognized uncertainty in Jacob's initial blessing, since it was obtained through deception. Rabbi Abahu noted that "the blessings were uncertain in his hand" until Isaac later summoned Jacob deliberately and blessed him again (Genesis 28:1), providing what Rabbi Elazar called proper "ratification" [3]. This second blessing, given when Isaac "entered fully into Rebekah's feelings," was pronounced "designedly, and with a cordial spirit," explicitly acknowledging Jacob as "the heir of the promise" [4].
Calvin emphasized that this confirmation was essential: Jacob needed assurance that he had not received "a curse instead of a blessing" given the deceptive means of obtaining it [7]. The voluntary second blessing removed any doubt, demonstrating that Isaac now recognized the divine will in Jacob's election, even if Rebekah had never revealed to him the oracle that "the elder shall serve the younger" [6].
The irrevocability thus rested on two foundations: the prophetic nature of patriarchal blessing as divine speech, and Isaac's subsequent deliberate confirmation that ratified what had been spoken under providential impulse.
Sources
- Hebrews “Hebrews 11:20 (KJV) — By faith Isaac blessed Jacob and Esau concerning things to come.”
- Project Gutenberg “Flavius Josephus, Antiquities of the Jews, CHAPTER 22, section 9: alteration was out of his power. A second afflatus then came upon him, and enabled him to foretell Esau's future behavior and foretell Esau's future behavior and fortune also.] 33 (return) [ Whether Jacob or his mother Rebeka were most blameable in this imposition upon Isaac in his old age, I cannot determine. However the blessing being delivered as a prediction of future events, by a Divine impulse, and foretelling things to befall to the posterity of Jacob and Esau in future ages, was for certain providential; and according to”
- Midrash Rabbah (Jewish (Rabbinic)) “Midrash Rabbah, Bereishit Rabbah 67:12: “Isaac summoned Jacob and he blessed him. He commanded him and said to him: Do not take a wife from the daughters of Canaan” (Genesis 28:1). “Isaac summoned Jacob and he blessed him” – Rabbi Abahu said: Because the blessings were uncertain in his hand. 23 The blessings which Jacob received when Isaac thought he was Esau were considered uncertain by Jacob. Where were they reinforced in his hand? It is here, “Isaac summoned Jacob.” 24 Isaac blessed him at his own initiative. Rabbi Elazar said: Ratification of a document is only by its signatories, so that ”
- Genesis (Presbyterian) “Jamieson, Fausset & Brown on Genesis 28 (introduction): JACOB'S DEPARTURE. (Gen. 28:1-19) Isaac called Jacob and blessed him--He entered fully into Rebekah's feelings, and the burden of his parting counsel to his son was to avoid a marriage alliance with any but the Mesopotamian branch of the family. At the same time he gave him a solemn blessing--pronounced before unwittingly, now designedly, and with a cordial spirit. It is more explicitly and fully given, and Jacob was thus acknowledged "the heir of the promise."”
- CCEL (Reformed) “Calvin, Commentary on Genesis, Vol. 2 (Gen 24-50), section 5.4: required support of this kind: just as the Lord, in reiterating, frequently the same promises, derogates nothing either from himself or from his word, but rather confirms the certainty of that word to his servants, lest, at any time, their confidence should be shaken through the infirmity of the flesh. What I have said must also be kept in mind, that Isaac prayed, not as a private person, but as one furnished with a special command of God, to transmit the covenant deposited with himself to his son Jacob. It was also of the greates”
- Sefaria (Jewish (Kabbalistic/Philosophical)) “Ramban (Nachmanides) on Genesis 27:4: THAT MY SOUL MAY BLESS THEE. It was Isaac’s intent to bless Esau that he merit the blessing of Abraham to inherit the land and to become the one with whom G-d would make the covenant since he was the firstborn. It would appear that Rebekah never told Isaac of the prophecy which G-d had related to her, i.e., And the elder shall serve the younger , 199 Above, 25:23. else how would Isaac transgress the commandment of the Eternal, seeing that it shall not prosper . 200 Numbers 14:41. Now at first she did not tell it to him due to ethical modesty, for the verse”
- Genesis (Methodist/Wesleyan) “Adam Clarke on Genesis 28:1: And Isaac called Jacob - See note on Gen 27:46. And blessed him - Now voluntarily and cheerfully confirmed to him the blessing, which he had before obtained through subtlety. It was necessary that he should have this confirmation previously to his departure; else, considering the way in which he had obtained both the birthright and the blessing, he might be doubtful, according to his own words, whether he might not have got a curse instead of a blessing. As the blessing now pronounced on Jacob was obtained without any deception on his part, it is likely that it pro”