He pointed to the little children in the room and said they were the sheep and needed lots of guidance. Then the pastor put his hands out to the side, palms up in a dramatic gesture, and with raised eyebrows said to the children, "If you are the sheep, then who is the shepherd?" He was pretty obviously indicating himself.
A few seconds of silence followed, then one little boy said, "Jesus is the shepherd."
The young pastor, obviously caught by surprise, said to the boy, "Well, then, who am I?"
The boy thought for a moment and then said with a shrug, "I guess you must be a sheep dog."