Clement of Alexandria : Isaac is another type too (he can easily be taken in this other sense), this time of the Lord. He was a son, just as is the Son (he is the son of Abraham; Christ, of God). He was a victim, as was the Lord, but his sacrifice was not consummated, while the Lord's was. All he did was to carry the wood of his sacrifice, just as the Lord bore the wood of the cross. Isaac rejoiced for a mystical reason, to prefigure the joy with which the Lord has filled us, in saving us from destruction through his blood. — The Instructor Book 1 Origen of Alexandria : After these things, "Abraham took," it says, "the wood for the burnt offering, and laid it upon Isaac his son, and took the fire in his hands and the sword, and they went together." That Isaac himself carries for himself "the wood for the burnt offering," this is a figure that Christ also "Himself bore the cross for Himself," and yet to carry "the wood for the burnt offering" is the office of the priest. He becomes therefore himself both the victim and the priest. But also that which is added, "and they both went together," refers to this. For when Abraham as one about to sacrifice carried the fire and the knife, Isaac does not go after him, but with him, so that it might be shown that he performs the priesthood equally together with him. — HOMILIES ON Genesis 8.6