5 And what is the beginning? “When Jesus was born in Bethlehem of Judæa, in the days of Herod the king, behold, there came wise men from the east to Jerusalem.” While wise men followed under the auspices of a star, these believed not, with prophets even sounding in their ears. But wherefore does he mention to us both the time and the place, saying, “in Bethlehem,” and “in the days of Herod the king?” And for what reason does he add his rank also? His rank, because there was also another Herod, he who slew John: but that was a tetrarch, this a king. And the place likewise, and the time, he puts down, to bring to our remembrance ancient prophecies; whereof one was uttered by Micah, saying, “And thou, Bethlehem, in the land of Judah, art by no means the least among the princes of Judah;” and the other by the patriarch Jacob, distinctly marking out to us the time, and setting forth the great sign of His coming. For, “A ruler,” says he, “shall not fail out of Judah, nor a leader out of his loins, until He come for whom it is appointed, and He is the expectation of the Gentiles.”
And this again is worth inquiry, whence it was that they came to entertain such a thought, and who it was that stirred them up to this. For it does not seem to me to be the work of the star only, but also of God, who moved their soul; which same kind of thing He did also in the case of Cyrus, disposing him to let the Jews go. He did not however so do this as to destroy their free will, since even when He called Paul from above by a voice, He manifested both His own grace and Paul's obedience.
And wherefore, one may ask, did He not reveal this to all the wise men of the East? Because all would not have believed, but these were better prepared than the rest; since also there were countless nations that perished, but it was to the Ninevites only that the prophet was sent; and there were two thieves on the cross, but one only was saved. See at least the virtue of these men, not only by their coming, but also by their boldness of speech. For so that they may not seem to be a sort of impostors, they tell who showed them the way, and the length of their journey; and having come, they had boldness of speech: “for we have come,” that is their statement, “to worship Him:” and they were afraid neither of the people's anger, nor of the tyranny of the king. Whence to me at least they seem to have been at home also teachers of their countrymen. For they who here did not shrink from saying this, much more would they speak boldly in their own country, as having received both the oracle from the angel, and the testimony from the prophet.
Source: Homilies on the Gospel of St. Matthew (New Advent)