John Gill 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 greatly rejoice when I sing unto thee
Both with vocal and instrumental music; this is praising the Lord with joyful lips, (Psalms 63:5) ;

and my soul, which thou hast redeemed ;
signifying that it would not be lip labour, or bodily service, only that he should perform; but that his heart would go along with his lips in praise; and that under a sense of redeeming love, than which nothing can more strongly engage in such work, (Psalms 103:1–3) . For the redemption of the soul is exceeding precious; being the contrivance of infinite wisdom, the fruit of divine grace, and owing to the blood and sacrifice of Christ.