Jacob's Ladder

And he lighted on a spot, and slept there, for the sun was set; and he gathered of the stones of the place, and put them under his head. And he slept in that place; and he dreamed, and, behold, a ladder was set up on the earth, whose top reached to heaven; and the angels of God ascended and descended upon it. And the Lord stood above it

Genesis 28:11-13, as St Justin Martyr gives it

In olden time Jacob beheld a ladder erected reaching to heaven, and the angels of God ascending and descending upon it. But now, having been made man for man’s sake, He who is the Friend of man has crushed with the foot of His divinity him who is the enemy of man, and has borne up the man with the hand of His Christhood, and has made the trackless ether to be trodden by the feet of man.

Gregory Thaumaturgus, On All the Saints