The moment Esau walks in with his meal, the Targum Pseudo-Jonathan tells us something the Hebrew only hints at. "Izhak was moved with great agitation when he heard the voice of Esau, and the smell of his food rose in his nostrils as the smell of the burning of Gehennam" (Genesis 27:33).
The smell of Gehinnom. The stench of the pit where the wicked are refined after death.
Two meals, two fragrances
Moments earlier, Isaac had breathed in Jacob and smelled the incense of the Temple that had not yet been built. Now, with Esau in the tent, the air turns. The same nostrils that had smelled Eden now smell the furnace of judgment. Pseudo-Jonathan is drawing the starkest possible contrast. One son carries the scent of sanctity. The other carries the scent of punishment.
The rabbis read this vision as the moment Isaac finally understood whom he had blessed. The prophecy was confirmed by his own nose. Who is he, then, who hath got venison, and come to me? Isaac asks — and the answer, which he now knows, is Jacob. I have blessed him, and he shall, too, be blessed.
The irrevocable blessing
This is perhaps the most important line in the entire chapter. Once Isaac realizes what has happened, he does not revoke the blessing. He confirms it. He shall be blessed. The words, spoken over the right son, carry their own authority. Even Isaac cannot take them back.
The takeaway: a true blessing, once spoken in the right moment, does not return empty. Pseudo-Jonathan is teaching that the universe has ears and keeps a record. When Isaac felt the smell of Gehinnom, it was not a suggestion to change the blessing. It was a sign that the blessing had gone exactly where it needed to go.