And a stranger will they not follow. — The “ stranger” is any one other than their own shepherd, and the term is not to be limited to the “thief” and “robber” of John 10:1. The thought is of the flock following the shepherd to the pasture. On the road they would meet other persons whom they would not follow. Some would, as thieves and robbers, seek to lead them away, calling them by their names and imitating their shepherd’s cry; but they have, by long usage, got to know his voice, and will not follow a stranger.
But will flee from him. — A strange word is a source of alarm to them. With the known tone of the shepherd’s voice they have learnt to associate protection, guidance, food. His voice recalls these associations. A stranger’s voice is something unknown, and therefore feared. It is as the voice of a plundering Arab who has called the flock before, or as the cry of a wild beast who has broken into the fold at night. The associations with unfamiliar words are only of things which are evil.