Thou shalt catch men (esh zwgrwn). Periphrastic future indicative, emphasizing the linear idea. The old verb Zwgrew means to catch alive, not to kill. So then Peter is to be a catcher of men, not of fish, and to catch them alive and for life, not dead and for death. The great Pentecost will one day prove that Christ's prophecy will come true. Much must happen before that great day. But Jesus foresees the possibilities in Simon and he joyfully undertakes the task of making a fisher of men out of this poor fisher of fish.