motzei Shabbos: parashas Toldos 5782
Overall, Isaac must have recognized that he who received the blessing of the firstborn, was meant to receive that blessing, when he said, “he shall be blessed,” referring to Jacob, who used deceit to obtain the blessing. The gist of the meaning of Isaac’s words is “he shall remain blessed.” Did Isaac have an epiphany at that moment, that compelled him to acknowledge that Jacob was the one who was divinely meant to receive the blessing? Consider that the midrash says that when Jacob, who was wearing goat pelts, drew near to Isaac to receive the blessing, Isaac smelled the perfume of Gan Eden ((Garden of Eden).
The midrash further explains that when Esau entered Isaac’s tent, shortly after Jacob who received the blessing left, “Isaac trembled very exceedingly,” because he “saw” Gehenna opened up beneath Esau. In the plain sense of the verse, Isaac trembled, when he realized, he had already given the blessing away to Jacob. Yet, the drift of the midrash may be understood to imply that in an instant, Isaac realized that Esau was not worthy of receiving the blessings because his character did not reflect the values deemed appropriate for the next patriarch of the family.
The Ramban (Nachmanides) concedes that Isaac knew through the Ruach HaKodesh (Holy Spirit) that indeed the blessing rested upon Jacob when given to him. So, briefly put, “it was meant to be.” Therefore, Isaac accepted the turn of events as hasgacha peratis (divine guidance). For, unbenownst to Isaac, Rebecca had previously recevied a prophecy from H’Shem, that “the older would serve the younger” (Genesis ). In other words, that Esau would serve Jacob. And, so, she felt it necessary to make sure this outcome would take effect, by insisting that Jacob listen to her words, when she told him to pretend to be Esau, in order to obtain the blessing of the firstborn.