John Calvin Commentary Psalms 86:6

"Give ear, O Jehovah, unto my prayer; And hearken unto the voice of my supplications." — Psalms 86:6 (ASV)

Listen, O Jehovah! to my prayer. From the earnest repetition of his former requests in this and the subsequent verse, it is evident that he was oppressed with no ordinary degree of grief, and also agitated with extreme anxiety. From this example, we are taught that those who, having engaged in prayer once, immediately allow themselves to cease that exercise if God does not at once grant them their desire, betray the coldness and inconstancy of their hearts.

Nor is this repetition of the same requests to be thought superfluous; for by this means the saints, by little and little, discharge their cares into the bosom of God, and this importunity is a sacrifice of a sweet aroma before Him. When the Psalmist says, God will hear me when I cry in the day of trouble, he applies to himself the truth he had just stated: that God is merciful and gracious to all who call upon Him.