The possibility that there were sheep that belonged to other shepherds in the same sheep pen evidently reflects an ancient custom, in which various shepherds brought their sheep to the same pen in the evening, to be guarded during the night by the gatekeeper. In the morning each shepherd would come to the pen and call his own sheep, and they would then follow him. Though in many parts of the world sheep are herded (that is, driven by shepherds), in the Middle East shepherds still walk ahead and their sheep follow them. It may be necessary to indicate by means of a marginal note these facts concerning shepherding in ancient times; otherwise, the story may appear to be anomalous and the analogies misleading.

In the Greek sentence structure, someone else is in the emphatic position. The word means literally “stranger,” and it appears as such in most translations. Good News Translation translates someone else, because in the present context the emphasis is not that the person involved is a stranger, but that he is not the sheep’s own shepherd.

Because they do not know his voice is literally “because they do not know the voice of strangers.” In Greek the first clause has the singular “stranger” (Good News Translation someone else), while here it has the plural “strangers.” In English it is more natural to be consistent throughout, using either a singular or a plural in both instances. Thus Good News Translation uses a singular in both places: someone else … his (voice).

In this context know must be understood in the sense of “recognize,” for example, “because they do not recognize his voice” or “because they do not recognize the voice as being that of their shepherd” or “… the one who takes care of them.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .