Sing unto the Lord... — It was as though heaviness had endured for a night, and joy had come in the morning. As with so many of the Psalms (Psalms 22:22 is, perhaps, the most striking parallel), what began in a cry De profundis ends in a Hallelujah.
Related Commentaries of Jeremiah 20:13
Jeremiah 20:13
13 Sing unto the LORD, praise ye the LORD: for he hath delivered the soul of the poor from the hand of evildoers.