Misericordiam et judicium. The prophet exhorteth all by his example, to follow mercy and justice.

 1 A psalm for David himself. Mercy and judgment I will sing to thee, O Lord: I will sing,  2 And I will understand in the unspotted way, when thou shalt come to me. I walked in the innocence of my heart, in the midst of my house.  3 I did not set before my eyes any unjust thing: I hated the workers of iniquities.  4 The perverse heart did not cleave to me: and the malignant, that turned aside from me, I would not know.  5 The man that in private detracted his neighbour, him did I persecute. With him that had a proud eye, and an unsatiable heart, I would not eat.

[2] "I will understand": That is, I will apply my mind, I will do my endeavour, to know and to follow the perfect way of thy commandments: not trusting to my own strength, but relying on thy coming to me by thy grace.

 6 My eyes were upon the faithful of the earth, to sit with me: the man that walked in the perfect way, he served me.  7 He that worketh pride shall not dwell in the midst of my house: he that speaketh unjust things did not prosper before my eyes.  8 In the morning I put to death all the wicked of the land: that I might cut off all the workers of iniquity from the city of the Lord.