Jamieson, Fausset and Brown on Psalms 73:1

PSALM 73

Psa 73:1-28. Of Asaph--(see Introduction). God is good to His people. For although the prosperity of the wicked, and the afflictions of the righteous, tempted the Psalmist to misgivings of God's government, yet the sudden and fearful ruin of the ungodly, seen in the light of God's revelation, reassures his heart; and, chiding himself for his folly, he is led to confide renewedly in God, and celebrate His goodness and love.

1. The abrupt announcement of the theme indicates that it is the conclusion of a perplexing mental conflict, which is then detailed (compare Jr 12:1-4).

Truly--or, "Surely it is so."

clean heart--(Psa 18:26) describes the true Israel.