The appearance of Elijah on the mountain led to a discussion of his role as Messiah's forerunner. This conversation developed as the disciples followed Jesus down the mountain.
9:9 Jesus again commanded secrecy (cf. 1:34, 43-44; 3:11-12; 5:43; 7:36; 8:30).217If the multitudes heard about this demonstration of His glory, it would only fuel the fires of popular messianism that created pressure for Jesus to depart from God's will. This is the last command to maintain secrecy in this Gospel. It is also the only one with a time limit. The people the disciples would tell the transfiguration story to would only understand it after Jesus arose from the dead. With His resurrection behind them, they could appreciate the fact that He would return in glory to establish the messianic kingdom.
9:10 The Old Testament taught a resurrection of the dead (Dan. 12:2; cf. John 11:24), but the disciples could not harmonize that revelation with Jesus' statement that He would rise three days after He died (8:31). The whole idea of Messiah dying was incomprehensible to them.
9:11 Rather than asking for clarification about the resurrection issue the disciples raised questions about the larger problem of Messiah dying. If Jesus was the Messiah and He would die, what did the scribes' teaching about Elijah being the forerunner of Messiah mean (Mal. 3:1-4; 4:5-6)? They taught that he would turn the hearts of the people back to God, but Elijah had not appeared and most of the people had not repented.
9:12 Jesus affirmed the scribes' interpretation of the prophecy about Elijah. He went on to explain that that interpretation did not invalidate what He had just predicted about His own sufferings and shameful rejection (Ps. 22; Isa. 52:13-53:12).
9:13 The disciples thought Elijah still had to come, but Jesus explained that he had come. His enemies had done to him what the Old Testament recorded. Jesus was speaking of John the Baptist (Matt. 17:13). The Old Testament passage to which Jesus referred was 1 Kings 19:1-3 and 10. There Ahab, and especially Jezebel, swore to kill Elijah. They "wished"to execute him. This is exactly what "King"Herod Antipas, and especially Herodias, really did to John the Baptist.218
"In this case Scripture had foretold the future not by prophecy but by a type. The fate intended for Elijah (I Kings xix. 2, 10) had overtaken John."219
Evidently Mark did not mention John the Baptist as the fulfillment of this prophecy, as Matthew did, because his identity is obvious to the careful reader. The fulfillment was not complete, however, because someone will come in the spirit and power of Elijah to prepare the way before Messiah's second coming (Mal. 4:5; cf. Rev. 11).
This discussion clarified for the disciples and for Mark's readers how Jesus' messiahship harmonized with Old Testament prophecy that seems to contradict it. Disciples of Jesus must have no doubts about His being the Son of Man, especially since they can anticipate testing through suffering for their faith. The importance of strong faith comes through in the next incident that Mark recorded.
