Evidently Jesus made this prediction in the upper room before the institution of the Lord's Supper. Mark probably inserted it here in his narrative because of its logical connection with Jesus' arrest in Gethsemane.
14:27-28 We should understand the meaning of "fall away"(Gr. skandalisthesesthe, cf. 4:17; 6:3; 9:42-47) in the light of the prophecy that Jesus said predicted it (Zech. 13:7). Zechariah did not mean that the sheep would abandon the shepherd permanently much less that they would cease to be what they were. He pictured the flock fleeing from the shepherd because someone attacked him. That is precisely what the disciples did when the authorities arrested and executed Jesus. Later those sheep rallied around the Shepherd. Jesus announced His leading them as a shepherd to Galilee later (v. 28). Again He spoke of His resurrection immediately after announcing His death (vv. 24-25).
Jesus attributed the Shepherd's striking to God. He changed the Zechariah passage slightly. Clearly Jesus viewed Himself as God's Suffering Servant (Isa. 53:4-6). This point would have helped the disciples accept Jesus' fate.
14:29-30 Peter refused to allow the possibility that he would forsake Jesus even though the other disciples might (cf. John 21:15). Jesus informed Peter that his defection would really be worse than that of the other disciples. He introduced His warning with the customary solemn affirmation and explained that the denial was not only certain but imminent. Furthermore Peter would repeat it three times in spite of the rooster's double warning. Mark alone referred to the second crowing probably because of Peter's recollection of the event. The word Jesus used for "deny"or "disown"(Gr. aparnese) is a strong one meaning "deny utterly."
14:31 Jesus' reply should have caused Peter to realize his weakness and seek help. Instead he dug in his heels and virtually told Jesus that he would die to prove Him wrong. He kept affirming excessively (Gr. ekperissos, used only here in the New Testament) that he would definitely not deny Jesus. Peter did not know how weak he was, a problem most disciples of Jesus share with him. He would have to learn the hard way, through failure. Peter led the other disciples in denying that they would deny Jesus.345
This pericope is a strong warning for all disciples. When facing persecution for one's allegiance to Jesus, one should not trust in the strength of his or her own commitment. He or she should trust in God who can supply the grace needed to remain faithful (cf. 9:14-29).
