St. Mark is here careful to state that what St. Matthew describes as "the word spoken by God" was to be found in the book of Moses (Exodus 3:5), in the place concerning the Bush ( ἐπὶ τῆς βάτου), as it is correctly rendered in the Revised Version.
Our Lord might have brought yet clearer proofs out of Job, Daniel, Ezekiel, etc.; but in his wisdom he preferred to allege this out of Moses and the Pentateuch, because, whatever the views of the Sadducees may have been as to other parts of the Old Testament, these books of Moses they readily acknowledged.
I am the God of Abraham, and the God of Isaac, and the God of Jacob. The force of the argument is this, that "God is not the God of the dead, but of the living." Their souls are still alive; and if these patriarchs are still alive, there will be a resurrection.
If men are to live for ever, they will, sooner or later, live again in the completeness of their being, namely, of body and soul and spirit. Our Lord would, therefore, say this: "In a few days you will put me to death; but in three days I shall rise again from the dead.
And after that, in due time I shall raise them from the dead at the last day, and bring them in triumph with me into heaven." The Sadducees and the Epicureans denied the resurrection, because they denied the immortality of the soul; for these two doctrines hang together.
For if the soul is immortal, then, since it naturally depends upon the body, it is necessary that the body should rise. Otherwise the soul would continue to exist in a dislocated state, and would only obtain a divided life and an imperfect existence.
Hence our Lord here distinctly proves the resurrection of the body from the immortality of the soul. When he speaks of Abraham, Isaac, and Jacob, he does not speak of their souls only, but of their whole being.
Therefore, though they are for a time dead to us, yet they live to God, and sleep, as it were, because ere long God will raise them from death, as from a sleep, to a blessed and endless life. For all, though they have passed out of our sight, still live to him.