9 “But the sheep did not hear them.” This is a more important point, “the sheep did not hear them.” Before the advent of our Lord Jesus Christ, when He came in humility in the flesh, righteous men preceded, believing in the same way in Him who was to come, as we believe in Him who has come. Times vary, but not faith. For verbs themselves also vary with the tense, when they are variously declined. He is to come, has one sound; He has come, has another: there is a change in the sound between He is to come, and He has come: yet the same faith unites both—both those who believed that He would come, and those who have believed that He has come.
At different times, indeed, but by the one doorway of faith, that is, by Christ, do we see that both have entered. We believe that the Lord Jesus Christ was born of the Virgin, that He came in the flesh, suffered, rose again, ascended into heaven: all this, just as you hear verbs of the past tense, we believe to be already fulfilled. In that faith a partnership is also held with us by those fathers who believed that He would be born of the Virgin, would suffer, would rise again, would ascend into heaven; for to such the apostle pointed when he said, “But we having the same spirit of faith, according as it is written, I believed, and therefore have I spoken; we also believe, and therefore speak.” The prophet said, “I believed, therefore have I spoken:” the apostle says, “We also believe, and therefore speak.”
But to let you know that their faith is one, listen to him saying, “Having the same spirit of faith, we also believe.” So also in another place, “For I would not have you ignorant, brethren, how that all our fathers were under the cloud, and all passed through the sea: and were all baptized unto Moses in the cloud and in the sea; and did all eat the same spiritual meat, and did all drink the same spiritual drink.” The Red Sea signifies baptism; Moses, their leader through the Red Sea, signifies Christ; the people, who passed through, signify believers; the death of the Egyptians signifies the abolition of sins.
Under different signs there is the same faith. It is with different signs as with different words [verbs]; for verbs change their sounds through the tenses, and verbs are indeed nothing else than signs. For they are words because of what they signify: take away the meaning from a word, and it becomes a senseless sound. All, therefore, have become signs. Was not the same faith theirs by whom these signs were employed, and by whom were foretold in prophecy the very things which we believe?
Certainly it was: but they believed that they were yet to come, and we, that they have come. In like manner does he also say, “They all drank the same spiritual drink;” “the same spiritual,” for it was not the same material [drink]. For what was it they drank? “For they drank of the spiritual Rock that followed them; and that Rock was Christ.” See, then, how that while the faith remained, the signs were varied. There the rock was Christ; to us that is Christ which is placed on the altar of God.
And they, as a great sacramental sign of the same Christ, drank the water flowing from the rock: what we drink is known to believers. If one's thoughts turn to the visible form, the thing is different; if to the meaning that addresses the understanding, they drank the same spiritual drink. As many, then, at that time as believed, whether Abraham, or Isaac, or Jacob, or Moses, or the other patriarchs or prophets who foretold of Christ, were sheep, and heard Christ. His voice, and not another's, did they hear.
The Judge was present in the person of the Crier. For even when the judge speaks through the crier, the clerk does not make it, The crier said; but the judge said. But others there are whom the sheep did not hear, in whom Christ's voice had no place—wanderers, uttering falsehoods, prating inanities, fabricating vanities, misleading the miserable.
Source: Tractates on the Gospel of John (New Advent)