Whereas Psalm 73 is on the sufferings of the seeking saints, Psalm 74 is on the desolation of the house of God.
Verses 1 through 11 are the psalmist's painful presentation of the perpetual ruins and damages in the sanctuary of God. "Why, O God, have You cast us off forever?/Why does Your anger smoke against the sheep of Your pasture?/Remember Your assembly, which You have purchased of old,/Which You have redeemed as the tribe of Your inheritance,/And this Mount Zion, on which You dwell" (vv. 1-2). These verses indicate that the psalmist was concerned about two things—God's people and God's dwelling place. Both God's people and His dwelling place had been damaged. Regarding this, the psalmist was deeply disappointed.
Verses 12 through 23 are a desperate cry for God's interest according to His power and based on His covenant. The psalmist did not pray for his own interest—he prayed for God's interest. He cried out to God for God's interest according to His power as described in verses 13 through 17. Then in verse 20 the psalmist said to God, "Regard the covenant." Here he seemed to be saying, "O God, You must regard the covenant which You made with our fathers Abraham, Isaac, and Jacob. You cannot forget it. You may disregard us, for we are evil, but You cannot disregard the covenant which You made."
The psalmist's prayer here is an example of the best kind of prayer—the prayer that is for God's interest, that is according to God's power, and that is based upon God's faithfulness to His covenant. We all need to learn to pray in this way. I believe that God heard this prayer of the psalmist and answered it, for eventually He came in to restore the ruined sanctuary.