John Calvin Commentary Psalms 119:82

"Mine eyes fail for thy word, While I say, When wilt thou comfort me?" — Psalms 119:82 (ASV)

My eyes have grown dim in looking for your word. This verse is very similar to the previous one, applying to the eyes what had previously been said about the soul. The only difference is that, instead of longing for salvation or help, the expression used here is longing for God’s word of promise; for salvation is an act, as it is called, and consists in its effect, whereas a promise keeps us suspended in expectation.

God may not immediately or openly perform what He has promised. In this case, since He promises us help only in His word, there is no other way we can hope for help than by relying on His word. Therefore, as the word in order precedes the help that God provides—or rather, as it is the way it is presented to us—the prophet, when sighing for salvation, very appropriately declares that he kept his eyes fixed on the Divine word until his sight failed him.

Here, the wonderful and incredible power of patience under the infirmity of the flesh is presented to us: when, being faint and deprived of all strength, we turn to God for help, even while it is hidden from us. In short, the prophet, to prevent any supposition that he was too weak or fainthearted, indicates that his fainting was not without cause. In asking God, When will you comfort me? he shows clearly enough that he was, for a long time, as it were, cast off and forsaken.