4 And Joseph also went up from Galilee, out of the city of Nazareth, into Judaea, unto the city of David, which is called Bethlehem; (because he was of the house and lineage of David:)
[AD 253] Origen of Alexandria on Luke 2:1-5
To those who attentively consider it, there seems to be expressed a kind of sacrament, in its being necessary that Christ should be put down in the registration of the whole world; in order that His name being written with all, He might sanctify all, and being placed in the census with the whole world, He might impart to the world the communion of Himself.

[AD 339] Eusebius of Caesarea on Luke 2:1-5
It was the forty second year of the reign of Augustus and twenty-eight years after the oppression of Egypt and the death of Antony and Cleopatra when Jesus was born in Bethlehem according to the prophecies concerning him. Flavius Josephus mentions this census in the time of Quirinius, adding another account about the sect of Galileans that arose at about the same time. Luke, among our writers, mentions this sect in Acts, saying, “After him Judas the Galilean arose in the days of the census and drew some people after him. He also perished, and all who followed him were scattered.”

[AD 397] Ambrose of Milan on Luke 2:1-5
He has rightly added the name of the governor, to mark the course of time. For if the names of the Consuls are affixed to the tables of prices, how much more ought the time to be noted down, of that event which was the redemption of all men?

There is described a secular registration, implied a spiritual, to be laid before the King not of earth but of Heaven; a registering of faith: a census of souls. For the old census of the Synagogue was abolished, a new census of the Church was preparing. And to decide that the census was not of Augustus, but of Christ, the whole world is ordered to be registered. For who could demand the registration of the whole world but He who had dominion over it, for the earth is not of Augustus, but the earth is the Lord's? (Ps. 24:1.)

This was then the first public enrolment of souls to the Lord, to Whom all enrol themselves not at the voice of the crier, but of the Prophet, who says, O clap your hands, all ye people. (Ps. 47:1.) But in order that men might know that it was an enrolment of righteousness, there came up to it Joseph and Mary, the just man and the virgin. He who was to be guardian of the Word and she who was to bring it forth.

[AD 407] John Chrysostom on Luke 2:1-5
(in diem natal. Christi.) It was the Lord who directed Augustus to give this edict, that he might minister unto the coming of the Only-begotten; for it was this edict that brought Christ's mother into her country as the prophets had foretold, namely, to Bethlehem of Judæa, according to the word, to a city of David, which is called Bethlehem.

[AD 407] John Chrysostom on Luke 2:1-5
A feast day is about to arrive, and it is the most holy and awesome of all feasts. It would be no mistake to call it the chief and mother of all holy days. What feast is that? It is the day of Christ’s birth in the flesh.It is from this day that the feasts of the theophany, the sacred Pasch [Passover], the ascension and Pentecost had their source and foundation. Had Christ not been born in the flesh, he would not have been baptized, which is the theophany or manifestation. Nor would he have been crucified, which is the Pasch. Nor would he have sent down the Spirit, which is Pentecost. Therefore, just as different rivers arise from a single source, these other feasts have their beginnings in the birth of Christ.

[AD 444] Cyril of Alexandria on Luke 2:1-5
(non occ.) It is said that she was espoused, to imply that nothing more than espousals preceded the conception; for it was not by man's seed that the Holy Virgin conceived.

[AD 444] Cyril of Alexandria on Luke 2:1-5
The Evangelist says that Mary was engaged to be married to Joseph, to show that the conception had taken place only upon her engagement, and that the birth of the Emmanuel was miraculous, and not in accordance with the laws of nature. For the Virgin did not bear from the emission of man’s seed. And why was this so? Christ, who is the first fruits of all, the second Adam according to the Scriptures, was born of the Spirit, that he might transmit the grace (of the spiritual birth) to us also. For we too were intended no longer to bear the name of sons of men, but rather of God. We have obtained the new birth of the Spirit in Christ first, that he might be “foremost among all,” as Paul declares.And the occasion of the census conveniently caused the virgin to go to Bethlehem, so that we might see another prophecy fulfilled. For it is written, “But you, Bethlehem Ephratha, who are little to be among the clans of Judah, from you shall come forth for me one who is to be ruler in Israel!”
Some argue that if he were brought forth in the flesh, the Virgin was corrupted. If she were not corrupted, then he was brought forth only in appearance. We reply, “the Lord, the God of Israel, has entered in and gone out, and the gate remains closed.” If, moreover, the Word was made flesh without sexual intercourse, being conceived altogether without seed, then he was born without injury to her virginity.

[AD 604] Gregory the Dialogist on Luke 2:1-5
(Hom. 8. in Ev.) But the registering of the whole world when our Lord was about to be born was mystical; for He appeared in the flesh Who should write down the names of His own elect in eternity.

[AD 735] Bede on Luke 2:1-5
The Son of God, about to be born in the flesh, as by His birth of a virgin He showed that the grace of virginity was most pleasing in His sight, is therefore begotten in the most peaceful time of the world, because He taught men to seek peace, and condescends to visit those who follow it. But there could be no greater sign of peace than for the whole world to be brought together under one taxing, while its ruler Augustus reigned with so great peace for the twelve years, about the time of our Lord's nativity, that war having been quelled throughout the whole world, there seemed to be a literal fulfilment of the Prophet's prediction, They shall beat their swords into ploughshares, &c.

St. Luke points out, that this taxing was either the first of those which comprehended the whole world, for before this very many parts of the earth are often mentioned as having been taxed; or first began at that time when Cyrinus was sent into Syria.

Now the registration of property was so appointed by Divine guidance, that every one was ordered to go into his own country, as it follows, And they all went to be taxed, every one to his own city. Which so came to pass, in order that the Lord, conceived in one place, born in another, might the more easily escape the fury of the crafty Herod. Hence it follows: Now Joseph also went up from Galilee.

And He most perfectly fulfilled what the name Augustus signifies, in that He was both desirous and able to increase (augere) His own.

As at that time in the reign of Augustus and under the governorship of Cyrinus, every one went to his own city to make returns of his property; so now when Christ reigns through His teachers (the governors of the Church) ought we to make returns of righteousness.

Our city and country is the resting-place of the blessed, to which we ought to be travelling with daily increasing virtues. But day by day does Holy Church wait upon her Teacher, and going up from the course of worldly business (which the name of Galilee signifies) to the city of Judah, i. e. the city of confession and praise, make returns of her devotion to the Eternal King. She, after the example of the blessed Virgin Mary, a Virgin has conceived us of the Spirit. Though espoused to another, she is made fruitful by Him; and while visibly joined to the Pontiff who is placed over her, is invisibly filled with the graces of the Spirit. And hence Joseph is well interpreted increased, declaring by his very name, that the earnestness of the master speaking is of no avail, except he receive increasing help from above, that he may be heard.

[AD 735] Bede on Luke 2:1-5
He chose a time of utmost peace as the time when he would be born because this was the reason for his being born in the world, that he might lead the human race back to the gifts of heavenly peace. And, indeed it is written: “For he is our peace, who has made us both one,” that is, he who as a kind mediator and reconciler has made one house of God of angels and humanity. Jesus was born in a time of peace, so that even by the circumstance of the time he might teach that he was the very one of whom the prophecy sent before him spoke: “His sovereignty will be multiplied, and there will be no end of peace.”

[AD 1107] Theophylact of Ohrid on Luke 2:1-5
Because it was fit also that at Christ's coming the worship of many Gods should cease, and one God only be worshipped, one king is described as ruling the world.

[AD 1274] Ancient Greek Expositor on Luke 2:1-5
(Metaphrastes et Alexander ander Monachus.) Christ is born also at a time when the princes of Judah had failed, and the kingdom was transferred to Roman governors, to whom the Jews paid tribute; and then was fulfilled the prophecy, saying, There shall not fail a leader from Judah, nor a prince from between his feet, until he shall come who is to be sent. (Gen. 49:10.) And now when Cæsar Augustus was in the 42d year of his reign, there went forth an edict from him that all the world should be taxed for the payment of tribute, the management of which he committed to a certain Cyrinus, whom he made governor of Judæa and Syria; and so it follows, This taxing was first made, &c.

(Irenæus cont. Hær. 1. 3. c. 11.) Now he added, a city of David, that he might declare that the promise made by God to David, namely, that from the fruit of his loins there should go before him a king for ever, (2 Sam. 7:12.) was already fulfilled. Whence it follows, Because he was of the house and lineage of David. (Ps. 132:11.) But since Joseph was of the family of David, it pleased the Evangelist to make known also that the Virgin herself was of the same family, because the Divine law enjoined marriages between those of the same line; and therefore it follows, With Mary his espoused wife.

[AD 420] Jerome on Luke 2:4-7
He will have it that Mary bore other sons, and he quotes the passage, "And Joseph also went up to the city of David to enroll himself with Mary, who was betrothed to him, being great with child. And it came to pass, while they were there, the days were fulfilled that she should be delivered, and she brought forth her first-born son." From this he endeavours to show that the term first-born is inapplicable except to a person who has brothers, just as he is called only begotten who is the only son of his parents.

Our position is this: Every only begotten son is a first-born son, but not every first-born is an only begotten. By first-born we understand not only one who is succeeded by others, but one who has had no predecessor. [Numbers 18:15] "Everything," says the Lord to Aaron, "that opens the womb of all flesh which they offer unto the Lord, both of man and beast, shall be yours: nevertheless the first born of man shall you surely redeem, and the firstling of unclean beasts shall you redeem." The word of God defines first-born as everything that opens the womb. Otherwise, if the title belongs to such only as have younger brothers, the priests cannot claim the firstlings until their successors have been begotten, lest, perchance, in case there were no subsequent delivery it should prove to be the first-born but not merely the only begotten. [Numbers 18:16] "And those that are to be redeemed of them from a month old shall you redeem, according to your estimation for the money of five shekels, after the shekel of the sanctuary (the same is twenty gerahs). But the firstling of an ox, or the firstling of a sheep, or the firstling of a goat, you shall not redeem; they are holy." The word of God compels me to dedicate to God everything that opens the womb if it be the firstling of clean beasts: if of unclean beasts, I must redeem it, and give the value to the priest. I might reply and say, Why do you tie me down to the short space of a month? Why do you speak of the first-born, when I cannot tell whether there are brothers to follow? Wait until the second is born. I owe nothing to the priest, unless the birth of a second should make the one I previously had the first-born. Will not the very points of the letters cry out against me and convict me of my folly, and declare that first-born is a title of him who opens the womb, and is not to be restricted to him who has brothers? And, then, to take the case of John: we are agreed that he was an only begotten son: I want to know if he was not also a first-born son, and whether he was not absolutely amenable to the law. There can be no doubt in the matter. At all events Scripture thus speaks of the Saviour, "And when the days of her purification according to the law of Moses were fulfilled, they brought him up to Jerusalem, to present him to the Lord (as it is written in the law of the Lord, every male that opens the womb shall be called holy to the Lord) and to offer a sacrifice according to that which is said in the law of the Lord, a pair of turtle-doves, or two young pigeons." If this law relates only to the first-born, and there can be no first-born unless there are successors, no one ought to be bound by the law of the first-born who cannot tell whether there will be successors. But inasmuch as he who has no younger brothers is bound by the law of the first-born, we gather that he is called the first-born who opens the womb and who has been preceded by none, not he whose birth is followed by that of a younger brother. Moses writes in Exodus, [Exodus 12:29] "And it came to pass at midnight, that the Lord smote all the first-born in the land of Egypt, from the first-born of Pharaoh that sat on his throne unto the first-born of the captive that was in the dungeon: And all the first-born of cattle." Tell me, were they who then perished by the destroyer, only your first-born, or, something more, did they include the only begotten? If only they who have brothers are called first-born, the only begotten were saved from death. And if it be the fact that the only begotten were slain, it was contrary to the sentence pronounced, for the only begotten to die as well as the first-born. You must either release the only begotten from the penalty, and in that case you become ridiculous: or, if you allow that they were slain, we gain our point, though we have not to thank you for it, that only begotten sons also are called first-born.

[AD 604] Gregory the Dialogist on Luke 2:4
And wrapped him in swaddling-clothes, and laid him in a manger, because there was no room for them in the inn."
[AD 735] Bede on Luke 2:4
Joseph also went up from Galilee, from the city of Nazareth, to Judah, to the city of David, etc. By divine arrangement, the census registration was decreed in such a way that everyone was ordered to go to their own homeland. Not only for the mystery we spoke of, but also so that the Lord, conceived elsewhere, born elsewhere, could evade the fury of Herod more easily. If He had been born to parents from Bethlehem, a cunning pursuer might have suspected their sudden flight, especially since everyone knew they were of the lineage of David, from whom Christ was to come. David himself bears witness to this with his name, homeland, and office. David, for his name means "hand of the strong" or "beloved." The name is derived both because he courageously struck down the giant and because he was handsome in appearance and had a pleasing face; but in a deeper mystery, prefiguring Him who was to be born of his house and family, who would singularly conquer the prince of this world, beautiful beyond the sons of men (Ps. 44), and He Himself born in Bethlehem and a shepherd of intellectual sheep, that is, the simple souls. We must particularly observe this great and benevolent humility of Him who consented not only to incarnate for us, but also to be born at a time when He would be registered in Caesar's census and thus subject Himself to servitude for our liberation. Peter suggests this to us as a path of His humility (for He did not come to change conditions, but minds): "Be subject," he says, "to every human creature for God's sake, whether to the king as the superior, or to governors as sent by him" (1 Peter 2). His co-apostle Paul also says: "Render therefore to all their dues: tribute to whom tribute is due; custom to whom custom; fear to whom fear; honor to whom honor. Owe no man anything, but to love one another" (Rom. 13).