Psalms 101:1

1I will sing of mercy and of judgment What David here says concerning singing must be understood by the reader as intimating that this psalm contains the substance of his meditations with himself, as to what kind of king he would be whenever he should be put in possession of the sovereign power which had been promised him. To sing therefore of mercy and of judgment, is equivalent to declaring in solemn terms, that he would be a just and an upright king. Augustine understands this as meaning that God is to be praised, whether he punish men with severity, or whether he show himself merciful to them; but this interpretation is too refined. David does not speak of God’s secret judgments, but of the due administration of the kingdom, that he might both by words and deeds fulfill his vocation. When he asserts, Unto thee, O Jehovah! will I sing psalms, he acknowledges that it was by the favor of God that he was appointed to so distinguished and honorable an office; for it would have been an act of presumptuous rashness for him to have thrust himself into it, at the mere impulse of his own mind. He very properly comprehends all princely virtues under these two particulars, mercy and judgment; for as it is the principal duty of a king to yield to every man his own right, so he is also required to possess a considerate love and compassion towards his subjects. Solomon therefore justly says, (Proverbs 16:12) “The throne is established by righteousness.”