A new song; either,
1. Newly composed. As God gives you fresh occasions, so do not you content yourselves with the old songs or psalms, made by the holy men of God, but make new ones suited to the occasions. But neither had all the righteous, to whom he speaks, Psalms 33:1, the gift of composing songs, nor was it of any necessity or importance that they should make new songs to praise God, at least for the works here mentioned, when there were so many made by David, and other holy prophets, for the use of God's church and people, when they had any such occasion. Or,
2. Renewed, or repeated, or sung again; in which sense Job saith his glory was new, or fresh in him, Job 29:20, i.e. renewed or continued from day to day; and the command of love is called new, 1 Thessalonians 13:34, because it was renewed and reinforced by Christ. So this song is here called new, not so much from the matter, as from the singing of it; because it was sung afresh, or again.