Luke 2:7-14: "7 And she gave birth to her firstborn son and wrapped him in swaddling cloths and laid him in a manger, because there was no place for them in the inn.
"8 And in the same region there were shepherds out in the field, keeping watch over their flock by night. 9 And an angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were filled with fear. 10 And the angel said to them, 'Fear not, for behold, I bring you good news of great joy that will be for all the people. 11 For unto you is born this day in the city of David a Savior, who is Christ the Lord. 12 And this will be a sign for you: you will find a baby wrapped in swaddling cloths and lying in a manger.' 13 And suddenly there was with the angels a multitude of the heavenly host praising God and saying, 14 'Glory to God in the highest, and on earth peace among those with whom he is pleased!'"
1 Timothy 3:16: "Great indeed, we confess, is the mystery of godliness: He was manifested in the flesh, vindicated by the Spirit, seen by angels, proclaimed among the nations, believed on in the world, taken up in glory."
1 John 1:1-3: "1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life - 2 the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us - 3 that which we have seen and heard we proclaim also to you, so that you too may have fellowship with us; and indeed our fellowship is with the Father and with his Son Jesus Christ."
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The text from Luke is the main referent, particularly in the first three verses ("The virgin bears a sinless boy," "Now in the manger we may see / God's Son from eternity," and so on). However, the other two texts that are cited also seem to be present in lines like "Clothed in flesh You came to earth" and "Here clothed in our poor flesh and bone."
The fourth verse mentions Jesus as "the Light Eternal":
The fourth verse mentions Jesus as "the Light Eternal":
The Light Eternal, breaking through,While this could have a number of Biblical sources, I first thought of John 8:12: "Again Jesus spoke to them, saying, 'I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.'" However, the phrase "children of the light" comes from Ephesians 5:8: "for at one time you were darkness, but now you are light in the Lord. Walk as children of light."
Made the world to gleam anew;
His beams have pierced the core of night,
He makes us children of the light.
Alleluia!