Isaiah 38:20

The Lord was ready to save me - He was prompt, quick to save me. He did not hesitate or delay.

Therefore we will sing my songs - That is, my family and nation. The song of Hezekiah was designed evidently not as a mere record, but to be used in celebrating the praises of God, and probably in a public manner in the temple. The restoration of the monarch was a fit occasion for public rejoicing; and it is probable that this ode was composed to be used by the company of singers that were employed constantly in the temple.

To the stringed instruments - We will set it to music, and will use it publicly (see the notes at Isaiah 5:12).