John Calvin Commentary Psalms 74:10

"How long, O God, shall the adversary reproach? Shall the enemy blaspheme thy name for ever?" — Psalms 74:10 (ASV)

How long, O God! shall the adversary reproach? Here it is implied that nothing caused them greater anguish than when they saw the name of God blasphemed by the ungodly. By this manner of praying, the object of the inspired writer was to kindle in our hearts a zeal for maintaining the Divine glory.

We are naturally too delicate and tender to bear calamities; but it is a decided proof of genuine godliness when the scorn that is cast upon God grieves and troubles our minds more than all our own personal sufferings. The poor Jews, undoubtedly, were assailed with various kinds of reproach under a most cruel tyrant and among a barbarous nation. But the prophet, speaking in the person of the whole Church, takes almost no account of the reproaches cast upon the people in comparison with the detestable blasphemies directed against God, according to the statement contained in Psalm 69:9, “The reproaches of them that reproached thee are fallen upon me.”

The phrase for ever is again added; for when the ungodly remain unpunished for a long time, this has a hardening effect and makes them more audacious, especially when the revilings they pour out against God seem to pass unnoticed by him. It is, therefore, added immediately after in the 11th verse,