From: Luke 1:5-25
The Birth of John the Baptist Foretold
 In the days of Herod, king of Judea, there was a priest named Zechariah, of the division of Abijah; and he had a wife of the daughters of Aaron, and her name was Elizabeth.  And they were both righteous before God, walking in all the commandments and ordinances of the Lord blameless.  But they had no child, because Elizabeth was barren, and both were advanced in years.
 Now while he was serving as priest before God when his division was on duty,  according to the custom of the priesthood, it fell to him by lot to enter the temple of Lord and burn incense.  And the whole multitude of the people were praying outside at the hour of incense.  And there appeared to him an angel of the Lord standing on the right side of the altar of incense.  And Zechariah was troubled when he saw him, and fear fell upon him.  But the angel said to him, "Do not be afraid, Zechariah, for your prayer is heard, and your wife Elizabeth will bear you a son, and you shall call his name John.  And you will have joy and gladness, and many will rejoice at his birth;  for he will be great before the Lord, and he shall drink no wine nor strong drink, and he will be filled with the Holy Spirit, even from his mother's womb.  And he will turn many of the sons of Israel to the Lord their God,  and he will go before him in the spirit and power of Elijah, to turn the hearts of the fathers to the children and the disobedient to the wisdom of the just, to make ready for the Lord a people prepared."
 And Zechariah said to the angel, "How shall I know this? For I am an old man, and my wife is advanced in years."  And the angel answered him, "I am Gabriel, who stand in the presence of God; and I was sent to speak to you, and to bring you this good news.  And behold, you will be silent and unable to speak until the day that these things come to pass, because you did not believe my words, which will be fulfilled in their time."  And the people were waiting for Zechariah, and they wondered at his delay in the temple.  And when he came out, he could not speak to them, and they perceived that he had seen a vision in the temple; and he made signs to them and remained dumb.  And when his time of service was ended, he went to his home.
 After these days his wife Elizabeth conceived, and for five months she hid herself, saying,  "Thus the Lord has done to me in the days when He looked on me, to take away my reproach among men."
6. After referring to the noble ancestry of Zechariah and Elizabeth, the evangelist now speaks of a higher type of nobility, the nobility of virtue: "Both were righteous before God." "For not everyone who is righteous in men's eyes is righteous in God's; men have one way of seeing and God another; men see externals but God sees into the heart. It can happen that someone seems righteous because his virtue is false and is practiced to win people's approval; but he is not virtuous in God's sight if his righteousness is not born of simplicity of soul but is only simulated in order to appear good.
"Perfect praise consists in being righteous before God, because only he can be called perfect who is approved by Him who cannot be deceived" (St. Ambrose, "Expositio Evangelii Sec. Lucam, in loc.").
In the last analysis what a Christian must be is righteous before God. St. Paul is advocating this when he tells the Corinthians, "But with me it is a very small thing that I should be judged by you or by any human court. It is the Lord who judges me. Therefore do not pronounce judgment before the time, before the Lord comes, who will bring to light the things now hidden in darkness and will disclose the purposes of the heart. Then every man will receive his commendation from God" (1 Corinthians 4:3ff). On the notion of the just or righteous man, see the note on Matthew 1:19.
8. There were twenty-four groups or turns of priests to which functions were allocated by the drawing of lots; the eighth group was that of the family of Abijah (cf. 1 Chronicles 24:7-19), to which Zechariah belonged.
9-10. Within the sacred precincts, in a walled-off area, stood the temple proper. Rectangular in form, there was first a large area which was called "the Holy Place", in which was located the altar of incense referred to in verse 9. Behind this was the inner sanctum, called "the Holy of Holies", where the Ark of the Covenant with the tablets of the Law used to be kept; only the high priest had access to this, the most sacred part of the temple. The veil or great curtain of the temple separated these two area from one another. The sacred building was surrounded by a courtyard, called the courtyard of the priests and outside this, at the front of the temple, was what was called the courtyard of the Israelites, where the people stayed during the ceremony of incensing.
10. While the priest offered incense to God, the people in the courtyard joined with him in spirit: even in the Old Testament every external act of worship was meant to be accompanied by an interior disposition of self-offering to God.
With much more reason should there be this union between external and internal worship in the liturgical rites of the New Covenant (cf. "Mediator Dei", 8), in the liturgy of the Church. Besides, this consistency befits the nature of man, comprised as he is of body and soul.
11. Angels are pure spirits, that is, they have no body of any kind; therefore, "they do not appear to men exactly as they are; rather, they manifest themselves in forms which God gives them so that they can be seen by those to whom He sends them" (St. John Damascene, "De Fide Orthodoxa," 2, 3).
In addition to adoring and serving God, angelic spirits act as God's messengers and channels of His providence towards men; this explains why they appear so often in salvation history and why Sacred Scripture refers to them in so many passages (cf., e.g. Hebrews 1:14).
Christ's birth was such an important event that angels were given a very prominent role in connection with it. Here, as at the Annunciation to Mary, the archangel St. Gabriel is charged with delivering God's message.
"It is no accident that the angel makes his appearance in the temple, for this announces the imminent coming of the true Priest and prepares the heavenly sacrifice at which the angels will minister. Let it not be doubted, then, that the angels will be present when Christ is immolated" (St. Ambrose, "Expositio Evangelii Sec. Lucam, in loc.").
12. "No matter how righteous a man be, he cannot look at an angel without feeling afraid; that is why Zechariah was alarmed: he could not but quake at the presence of the angel; he could not take the brightness that surrounded him" (St. John Chrysostom, "De Incomprehensibili Dei Natura"). The reason for this is not so much the angels' superiority to man as the fact that the grandeur of God's majesty shines out through the angel: "And the angel said to me, `Write this: Blessed are those who are invited to the marriage supper of the Lamb.' And he said to me, `These are true words of God.' Then I fell down at his feet to worship him, but he said to me, `You must not do that! I am a fellow servant with you and your brethren who hold the testimony of Jesus. Worship God'" (Revelation 19:9-10).
13. Through the archangel God intervenes in an exceptional way in the married life of Zechariah and Elizabeth; but the message he brings has much wider reference; it has significance for the whole world. Elizabeth is already quite old but she is going to have a son who will be called John ("God is gracious") and he will be the forerunner of the Messiah. This showed that "the fullness of time" (cf. Galatians 4:4) was imminent, for which all righteous people of Israel had yearned (cf. John 8:56; Hebrews 11:13).
"Your prayer is heard," St. Jerome comments, "that is to say, you are given more than you asked for. You prayed for the salvation of the people, and you have been given the Precursor" ("Expositio Evangelium Sec. Lucam, in loc."). Our Lord also sometimes gives us more than we ask for: "There is a story about a beggar meeting Alexander the Great and asking him for alms. Alexander stopped and instructed that the man be given the government of five cities. The beggar, totally confused and taken aback, explained, `I didn't ask for that much.' And Alexander replied, `You asked like the man you are; I give like the man I am" ([Blessed] J. Escriva, "Christ Is Passing By", 160). Since God responds so generously and gives us more than we ask for, we should face up to difficulties and not be cowed by them.
14-17. The archangel St. Gabriel gives Zechariah three reasons why he should rejoice over the birth of this child; first, because God will bestow exceptional holiness on him (verse 15); second, because he will lead many to salvation (verse 16); and third, because his whole life, everything he does, will prepare the way for the expected Messiah (verse 17).
In St. John the Baptist two prophecies of Malachi are fulfilled; in them we are told that God will send a messenger ahead of Him to prepare the way for Him (Malachi 3:1; 4:5-6). John prepares the way for the first coming of the Messiah in the same way as Elijah will prepare the way for His second coming (cf. St. Ambrose, "Expositio Evangelii Sec. Lucam, in loc."; St. Thomas Aquinas, "Commentary on St. Matthew", 17, 11, "in loc."). This is why Christ will say, "What did you go out to see? A prophet? Yes, I tell you, and more than a prophet. This is he of whom it is written, `Behold, I send My messenger before Thy face, who shall prepare Thy way before Thee'" (Luke 7:26-27).
18. Zechariah's incredulity and his sin lie not in his doubting that this message has come from God but in forgetting that God is almighty, and in thinking that he and Elizabeth are past having children. Later, referring to the conception of John the Baptist, the same angel explains to Mary that "with God nothing will be impossible" (Luke 1:37). When God asks us to take part in any undertaking we should rely on His omnipotence rather than our own meagre resources.
19-20. "Gabriel" means "might of God". God commanded the archangel Gabriel to announce the events connected with the incarnation of the Word; already in the Old Testament it was Gabriel who proclaimed to the prophet Daniel the time of the Messiah's coming (Daniel 8:15-26, 9:20-27). This present passage deals with the announcement of the conception and birth of Christ's Precursor, and it is the time same angel who will reveal to the Blessed Virgin the mystery of the Incarnation.
24. Elizabeth hid herself because of the strangeness of pregnancy at her age and out of a holy modesty which advised her not to make known God's gifts prematurely.
25. Married couples who want to have children, to whom God has not yet given any, can learn from Zechariah and Elizabeth and have recourse to them as intercessors. To couples in this situation [St] Monsignor Escriva de Balaguer recommended that "they should not give up hope too easily. They should ask God to give them children and, if it is His will, to bless them as He blessed the Patriarchs of the Old Testament. And then it would be advisable for both of them to see a good doctor. If in spite of everything God does not give them children, they should not feel frustrated. They should be happy, discovering in this very fact God's will for them. Often God does not give them children because He is `asking more'. God asks them to put the same effort and the same kind and gentle dedication into helping their neighbors as they would have put into raising their own children, without the human joy that comes from parenthood. There is, then, no reason for feeling they are failures or for giving way to sadness" ("Conversations", 96).
Here is the authoritative teaching of John Paul II on this subject: "It must not be forgotten, however, that, even when procreation is not possible, conjugal life does not for this reason lose its value. Physical sterility in fact can be for spouses the occasion for other important services to the life of the human person--for example, adoption, various forms of educational work, assistance to other families and to poor or handicapped children" ("Familiaris Consortio", 14).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.