Theophylact of Ohrid — as excerpted in the Catena Aurea on Mark 12:18-27

“But I say, I am the God of Abraham, the God of Isaac, and the God of Jacob. As if He had said, The God of the living, wherefore He adds, He is not the God of the dead, but of the living; for He did not say, I have been, but I am, as if they had been present. But some one perhaps will say, that God spake this only of the soul of Abraham, not of his body; to which I answer, that Abraham implies both, that is, soul and body, so that He also is the God of the body, and the body lives with God, that is, in God’s ordinance.”