Then Israel sang this song, Spring up, O well; sing ye unto it: Spring up, O well, etc. - This is one of the most ancient war songs in the world, but is not easily understood, which is commonly the case with all very ancient compositions, especially the poetic. See the remarks Exodus 15:1 (note), etc.
Related Commentaries of Numbers 21:17
Numbers 21:17
17 Then Israel sang this song, Spring up, O well; sing ye unto it: