And if we should ask for a second prophecy, which may appear to us to have a clear reference to Jesus, we would quote that which was written by Moses very many years before the advent of Christ, when he makes Jacob, on his departure from this life, to have uttered predictions regarding each of his sons, and to have said of Judah along with the others: “The ruler will not fail from Judah, and the governor from his loins, until that which is reserved for him come.” Now, any one meeting with this prophecy, which is in reality much older than Moses, so that one who was not a believer might suspect that it was not written by him, would be surprised that Moses should be able to predict that the princes of the Jews, seeing there are among them twelve tribes, should be born of the tribe of Judah, and should be the rulers of the people; for which reason also the whole nation are called Jews, deriving their name from the ruling tribe.
And, in the second place, one who candidly considers the prophecy, would be surprised how, after declaring that the rulers and governors of the people were to proceed from the tribe of Judah, he should determine also the limit of their rule, saying that “the ruler should not fail from Judah, nor the governor from his loins, until there should come that which was reserved for him, and that He is the expectation of the Gentiles.” For He came for whom these things were reserved, viz., the Christ of God, the ruler of the promises of God.
And manifestly He is the only one among those who preceded, and, I might make bold to say, among those also who followed Him, who was the expectation of the Gentiles; for converts from among all the Gentile nations have believed on God through Him, and that in conformity with the prediction of Isaiah, that in His name the Gentiles had hoped: “In Your name shall the Gentiles hope.” And this man said also to those who are in prison, as every man is a captive to the chains of his sins, “Come forth;” and to the ignorant, “Come into the light:” these things also having been thus foretold: “I have given You for a covenant of the people, to establish the earth, to cause to inherit the desolate heritage; saying to the prisoners, Go forth; and to them that are in darkness, Show yourselves.” And we may see at the appearing of this man, by means of those who everywhere throughout the world have reposed a simple faith in Him, the fulfilment of this prediction: “They shall feed in the ways, and their pastures shall be in all the beaten tracks.”
Source: Against Celsus (New Advent)