John Calvin Commentary Psalms 119:88

"Quicken me after thy lovingkindness; So shall I observe the testimony of thy mouth." — Psalms 119:88 (ASV)

Quicken me according to your goodness. This verse contains nothing new. In the beginning of it, David represents his life as depending on God’s mercy, not only because he was conscious of human frailty, but also because he saw himself daily exposed to death in multiplied forms, or rather, because he was convinced that if God’s power were withdrawn from him, he would be laid prostrate as if he were dead.

He next promises that when he is again restored to life, he will not be ungrateful but will duly acknowledge this as a blessing from God, not only with his tongue but also in his whole life. As the various instances in which God helps us and delivers us from dangers are so many new lives, it is reasonable that we should dedicate to His service whatever additional time is allotted to us in this world.

When the law is called the testimony of God’s mouth, by this praise its authority is very plainly asserted.