Text in red are my additions.
15. And it came to pass, after the angels departed from them into heaven, the shepherds said one to another: Let us go over to Bethlehem, and let us see this word that is come to pass, which the Lord hath shewed to us.
This word that is come to pass. The term “word” here, as in other places, simply means thing, i.e., this event which the angels had announced. Cf. on Luke 1:37.
Which the Lord hath showed to us; i.e., hath “revealed” to us. These words indicate that the shepherds had received an interior revelation from God to know the importance of the angelic announcement.
16. And they came with haste ; and they found Mary and Joseph, and the infant lying in the manger.
They came with haste. The shepherds were perhaps some little distance from the stable, some say about a mile.
17. And seeing, they understood of the word that had been spoken to them concerning this child.
They understood of the word; i.e., they understood the meaning of the announcement.
18. And all that heard, wondered; and at those things that were told them by the shepherds.
And at those things, etc. The “and” at the beginning of this clause is not found in the Greek and Syriac texts of St. Luke; hence there should be no stop after “wondered.” And all that heard wondered at those things & c.
19. But Mary kept all these words, pondering them in her heart.
Pondered them in her heart. While others wondered and talked about the marvellous things that had occurred in connection with the birth of our Lord, Mary remained silent, quietly revolving in her mind the great mystery of the Redemption, and the ancient prophecies, which had foretold it.
20. And the shepherds returned, glorifying and praising God, for all the things they had heard and seen, as it was told unto them.
Father Callan offers not notes on this verse.
21. And after eight days were accomplished, that the child should be circumcised, his name was called Jesus, which was called by the angel, before he was conceived in the womb.
After eight days; i.e., on the eighth day, when it was required, according to the Law, that the child should be circumcised.
Circumcised. Our Lord submitted to this painful operation, not because He stood in any need of it, since He was spotless; but in order: (a) to show respect and obedience to the existing Law; (b) in order that the Jews might have no pretext for accusing and rejecting Him; (c) to give sanction to the rite of circumcision. The ceremony of circumcision was performed, according to Jewish custom, not in the Temple, but at the home of the family, — in the case of our Lord— in the cave. It was ordinarily performed by the father, or head of the family, and in the presence of ten witnesses, who attested the child’s enrollment among the theocratic people.