Then Israel sang this song
Being affected with the free favour and good will of God towards them:
spring up, O well;
for the springing up of which they prayed in faith, believing in the promise of God, that it would spring up; and so encouraged one another not only to believe it, but even to sing on account of it before it actually did:
sing ye unto it;
or on account of it praise the Lord for it; or "answer to it" F13, it being their manner to sing their songs by responses, or alternately.
F13 (hl wne) "respondete ei", Montanus; "alternis canite ei", Tigurine version, Piscator.