Often some are righteous, but not in the sight of God, but in appearance and in the sight of men. And Zacharias and Elizabeth were righteous before God. The commandments are, for example: "Thou shalt not commit adultery", "Thou shalt not steal" (Exodus 20:14-15), and the statutes (in Church Slavonic - justifications) are, for example: "Whoever curses his father or his mother shall be put to death" (Exodus 21:17): for this is righteous. But know that the commandment can also be called justification, since it makes a person righteous and is even more God's justification. For on that day God will judge us, having the commandments as if by some kind of written justification, "If I had not come and spoken unto them, they would have had no sin" (John 15:22), and again: "The word which I have spoken, it shall judge him at the last day" (John 12:48). Why is "blameless" added to the words "walking in all the commandments"? Listen. Often some act according to the Law of God, but they do everything in order to show themselves to people (Matt. 23:5). Such are not blameless. But Zachariah also kept the commandments, and kept them blamelessly, and not in order to please people through their fulfillment.

     They had no children, for Elizabeth was barren, and both were already in old age. 

The wives of the righteous and the righteous themselves were often childless, so that you would know that the Law requires many children, not carnal, but spiritual. "Both were already advanced in years" both in body and in spirit, for in soul they were old, that is, they made great progress, putting ascents in the heart (Psalm 83:6) and having life as day and not night, doing decently as in the light (Romans 13:12, 13).

     Once, when he was serving before God in the order of his rank, by lot, as was usual with priests, it fell to him to enter the temple of the Lord for incense, and all the multitude of people prayed outside during the incense. 

Before God, only the pure perform the sacraments, but from the unclean God hides His face. "When did he come to cense?" Without a doubt, on the day of atonement, when one high priest entered the Holy of Holies, so that we might learn that just as this high priest, having entered the Holy of Holies, received fruit, so the Lord Jesus, the only and truly great Bishop, having entered the Holy of Holies, that is, with the flesh into heaven, received the fruit of His appearance in the flesh – our adoption as sons of God and salvation.

     Then an angel of the Lord appeared to him, standing on the right side of the altar of incense.

 An angel does not appear to everyone, but to a pure heart, as Zechariah was. The altar (in Church Slavonic - altar) is called incense because there was another altar - burnt offerings.