Isaac's scruples about blessing the son before him were not yet removed, for with his prophetical eye he foresaw that this one would have descendants who would vex the Lord. At the same time, it was revealed to him that even the sinners in Israel would turn penitents, and then he was ready to bless Jacob. He bade him come near and kiss him, to indicate that it would be Jacob who would imprint the last kiss upon Isaac before he was consigned to the grave- he and none other. When Jacob stood close to him, he discerned the fragrance of Paradise clinging to him, and he exclaimed, "See, the smell of my son is as the smell of the field which the Lord hath blessed."
Isaac Foresaw That Some of Jacob's Descendants Would Sin
Legends of the Jews 6:62