27 And now let us consider the glory which accompanies the birth, the wailing and the cradle. The Angel tells Joseph that the Virgin shall bear a Son, and that Son shall be named Emmanuel, that is, God with us. The Spirit foretells it through the prophet, the Angel bears witness; He that is born is God with us. The light of a new star shines forth for the Magi; a heavenly sign escorts the Lord of heaven. An Angel brings to the shepherds the news that Christ the Lord is born, the Saviour of the world.
A multitude of the heavenly host flock together to sing the praise of that childbirth; the rejoicing of the Divine company proclaims the fulfilment of the mighty work. Then glory to God in heaven, and peace on earth to men of good will is announced. And now the Magi come and worship Him wrapped in swaddling clothes; after a life devoted to mystic rites of vain philosophy they bow the knee before a Babe laid in His cradle. Thus the Magi stoop to reverence the infirmities of Infancy; its cries are saluted by the heavenly joy of angels; the Spirit Who inspired the prophet, the heralding Angel, the light of the new star, all minister around Him.
In such wise was it that the Holy Ghost's descent and the overshadowing power of the Most High brought Him to His birth. The inward reality is widely different from the outward appearance; the eye sees one thing, the soul another. A virgin bears; her child is of God. An Infant wails; angels are heard in praise. There are coarse swaddling clothes; God is being worshipped. The glory of His Majesty is not forfeited when He assumes the lowliness of flesh.
Source: On the Trinity (New Advent)