The Pulpit Commentary - Psalms 37:9
For evil-doers shall be out off . It is foolish to "fret" and rage and storm against the ungodly whom we see prospering, since they will certainly be "cut off " sooner or later—sooner rather than later, according to the belief of the writer (see Psalms 37:2 , Psalms 37:10 ). But those that wait upon the Lord (see Psalms 37:7 ), they shall inherit the earth. It is doubly foolish, since when the wicked are "cut off," as they will be assuredly some day, the godly will find themselves... read more
The Pulpit Commentary - Psalms 37:8
Cease from anger, and forsake wrath; i.e. such anger and such wrath as the prosperity of the wicked calls forth. Fret not thyself in any wise to do evil; rather, fret not thyself , only to do evil. No result could be looked for from the sort of "fretting" spoken of, but an evil one. If men will dwell unduly on the fact of the prosperity of the wicked, and brood upon it in their hearts, they will be apt, in the first instance, to envy the wicked, which is at once "to do evil;" and... read more