“And, behold, there appeared unto them Moses and Elias talking with him.”
King James Version (KJV)
17:3 There appeared Moses and Elijah - Here for the full confirmation of their faith in Jesus, Moses, the giver of the law, Elijah, the most zealous of all the prophets, and God speaking from heaven, all bore witness to him.
Mt 17:3 There appeared unto them Moses and Elijah. (1) Among all the prophets and saints of the Old Testament, these were the two, of which one had not died (2Ki 2:11), and the other had no sooner tasted of death than his body was withdrawn from under the dominion of death and of him that had the power of death (De 34:6; Jude 1:9). Both, therefore, came from hades, but from hades conquered. (2) Again, these two were the acknowledged heads and representatives, the one of the law, the other of the prophets Compare Mt 7:12. Talking with him. The subject of their conversation is given in Luke. It was "the decease" (exodus, departure, referring to his death and ascension) "which he should accomplish at Jerusalem" (Lu 9:31). In this brief interview between the greatest worthies of the old dispensation and the Founder of the new dispensation their conversation would be confined to the most important theme of earth and heaven. That was the Savior's death.