John Calvin Commentary Psalms 69:24

"Pour out thine indignation upon them, And let the fierceness of thine anger overtake them." — Psalms 69:24 (ASV)

Pour out your fury upon them. It is not surprising that David utters a lengthy series of imprecations, for we know well that the frantic enemies of the Church, whom he aimed to fill with terror, are not easily moved. He therefore raises his voice against them with greater vehemence, so that they might be led to cease from their wrongful and insolent conduct.

However, he primarily had true believers in view. When oppressed by calamities, they have no other support to lean on except for the voice they hear proceeding from God's mouth. This voice declares the terrible vengeance prepared for their enemies, if, indeed, they are among the reprobate.

As for those whose repentance and reformation offered some hope, David wished for them to be corrected by chastisements. But as for those whose repentance and reformation were hopeless, he prays that destruction may fall upon their heads, so that they might not escape the punishment appointed for them, which they had deserved.