John Calvin Commentary Psalms 71:23

"My lips shall shout for joy when I sing praises unto thee; And my soul, which thou hast redeemed." — Psalms 71:23 (ASV)

My lips shall rejoice when I sing to thee. In this verse David expresses more distinctly his resolution not to give thanks to God hypocritically, nor in a superficial manner, but to engage with unfeigned earnestness in this religious exercise. By the figures which he introduces, he briefly teaches us that praising God would be the source of his greatest pleasure; and thus he indirectly censures the profane mirth of those who, forgetting God, confine their congratulations to themselves in their prosperity. The scope of the last verse is to the same effect, implying that no joy would be sweet or desirable to him unless it was connected with praising God, and that celebrating his Redeemer’s praises would afford him the greatest satisfaction and delight.