Depart from evil, and do good. From words the psalmist proceeds to acts, and, in the briefest possible way, says all that can be said. First, he enjoins negative goodness—"depart from evil," i.e. do nothing that is wrong; break no laws of God, no command of conscience; have a conscience void of offence, both towards God and towards man.
Secondly, he requires positive goodness—"Do good;" i.e. actively perform the will of God from the heart; discharge every duty; practise every virtue; carry out the precepts of the moral law in every particular.
Seek peace, and pursue it. It is not clear why this virtue—one of many—is specially enjoined; but probably some circumstances of the time made the recommendation advisable.