John Calvin Commentary Psalms 88:13

"But unto thee, O Jehovah, have I cried; And in the morning shall my prayer come before thee." — Psalms 88:13 (ASV)

But to you have I cried, O Jehovah! There may have been a degree of immoderation in the language of the prophet, which, as I have granted, cannot be altogether vindicated; but still it was a sign of rare faith and piety to persevere as he did with unfailing earnestness in prayer. This is what is meant when he says that he made haste in the morning; by which he means we should not imagine that he slowly and coldly lingered until he was constrained by dire necessity. At the same time, he modestly intimates by these words that his pining away in long-continued miseries was not owing to his own sluggishness, as if he had not sought God. This is an example especially noteworthy, so that we may not become discouraged if it sometimes happens that our prayers are for a time unsuccessful, although they may proceed from the heart and be diligently persevered in.