51. Hereafter, &c.—The key to this great saying is Jacob's vision (Ge 28:12-22), to which the allusion plainly is. To show the patriarch that though alone and friendless on earth his interests were busying all heaven, he was made to see "heaven opened and the angels of God ascending and descending upon a" mystic "ladder reaching from heaven to earth." "By and by," says Jesus here, "ye shall see this communication between heaven and earth thrown wide open, and the Son of man the real Ladder of this intercourse."

     13. Quotation from Ps 110:1. The image is taken from the custom of conquerors putting the feet on the necks of the conquered (Jos 10:24, 25).