857. (Verse 3) And they sang, as it were, a new song. That this signifies, concerning the acknowledgment and confession of the Lord, is evident from the signification of a song, as denoting confession from joy of heart; and of a new song, as denoting the acknowledgment and confession of the Lord, thus His glorification; concerning which see above (n. 326).
Song is mentioned in many passages of the Word, and especially in David; and by this is signified the confession and glorification of God by singing. And where a new song is mentioned, it signifies the confession and glorification of the Lord; for this song is called new, because in the churches, before the Lord's Advent, Jehovah was celebrated by songs; but after the Lord came into the world, and made Himself manifest, the Lord also was celebrated by songs; but now in the church, hereafter to be established, which is meant by the New Jerusalem, the Lord alone will be celebrated. And because it was the same Lord in the ancient churches, but celebrated under the name of Jehovah, who is now called the Lord, and thus the song concerning Him, strictly, is not new, therefore it is said, as it were a new song. This therefore is called new, because for the New Church, hereafter to be established by the Lord.