Exodus 15:1 - Wesley's Explanatory Notes

Then sang Moses — Moses composed this song, and sang it with the children of Israel. Doubtless he wrote it by inspiration, and sang it on the spot. By this instance it appears that the singing of psalms, as an act of religious worship, was used in the church of Christ before the giving of the ceremonial law, therefore it is no part of it, nor abolished with it: singing is as much the language of holy joy, as praying is of holy desire. I will sing unto the Lord — All our joy must terminate in God, and all our praises be offered up to him, for he hath triumphed — All that love God triumph in his triumphs.