Book Three (Psalms 73-89) "Concerning the Sanctuary"
A Psalm of Asaph.
1: Truly God is good to Israel, even to such as are of a 
clean heart.
2: But as for me, my feet were almost gone; my steps had well nigh slipped.
3: For I was envious at the foolish, when I saw the prosperity of the wicked.
4: For there are no bands in their death: but their strength is firm.
5: They are not in trouble as other men; neither are they plagued like other men.
6: Therefore pride compasseth them about as a chain; violence covereth them as a garment.
7: Their eyes stand out with fatness: they have more than heart could wish.
8: They are corrupt, and speak wickedly concerning oppression: they speak loftily.
9: They set their mouth against the heavens, and their tongue walketh through the earth.
10: Therefore his people return hither: and waters of a full cup are wrung out to them.
11: And they say, How doth God know? and is there knowledge in the most High?
12: Behold, these are the ungodly, who prosper in the world; they increase in riches.
13: Verily I have cleansed my heart in vain, and washed my hands in innocency.
14: For all the day long have I been plagued, and chastened every morning.
15: If I say, I will speak thus; behold, I should offend against the generation of thy children.
16: When I thought to know this, it was too painful for me;
17: Until I went into the sanctuary of God; then understood I their end.
18: Surely thou didst set them in slippery places: thou castedst them down into destruction.
19: How are they brought into desolation, as in a moment! they are utterly consumed with terrors.
20: As a dream when one awaketh; so, O Lord, when thou awakest, thou shalt despise their image.
21: Thus my heart was grieved, and I was pricked in my reins.
22: So foolish was I, and ignorant: I was as a beast before thee.
23: Nevertheless I am continually with thee: thou hast holden me by my right hand.
24: Thou shalt guide me with thy counsel, and afterward receive me to glory.
25: Whom have I in heaven but thee? and there is none upon earth that I desire beside thee.
26: My flesh and my heart faileth: but God is the strength of my heart, and my portion for ever.
27: For, lo, they that are far from thee shall perish:
thou hast destroyed all them that go a whoring from thee.
28: But it is good for me to draw near to God: I have put my trust in the Lord GOD, that I may declare all thy works.
1. clean heart = right attitude.