Rabbi Simeon said: In the hour when Isaac was bound, he lifted up his eyes heavenwards and saw the glory of the Shekhinah, as it is written, "For man shall not see me and live" (Ex. 33:20). Instead of death his eyes grew dim in his old age, as it is said, "And it came to pass, that when Isaac was old, that his eyes were dim, so that he could not see" (Gen. 27:1). Hence thou mayest learn that the blind man is as though he were dead.
The night-fall of the festival day of Passover came, and Isaac called unto Esau his elder son, and said: O my son! To-night the heavenly ones utter songs, on this night the treasuries of dew are opened; on this day the blessing of the dews (is bestowed). Make me savoury meat whilst I am still alive, and I will bless thee. || The Holy Spirit rejoined, saying to him: "Eat thou not the bread of him that hath an evil eye, neither desire thou his dainties" (Prov. 23:6). He went to fetch it, and was delayed there. Rebecca said to Jacob his (other) son: On this night the treasuries of dew will be opened, and on this night the angels utter a song. Make savoury meat for thy father, that he may eat and whilst he still lives he may bless thee.