deviseth [chashab] mischief ['aven] upon his
bed [mishkab]; he setteth [yatsab] himself in a way [derek]
that is not good [towb]; he abhorreth [ma'ac] not evil [ra`]. KJV-Interlinear
4 He plots
trouble while on his bed; he sets himself in a way that is not good; he does
not reject evil. ESV
The summary of this verse, is that all wickedness, all disregard of truth, all indifference, all reluctance to learn, is not as a result of some spontaneous or emotional action, it arises out of a calm and deliberate process. A pattern of intent, that spans across the life of the individual.
The bed here, is symbolized as the place of rest, of pondering, of peaceful methodical thinking and relaxation, and privacy.
Devising mischief, includes anything and everything that is not in compliance with truth, doctrine, or the spiritual life. This can range in anything from indifference to a daily study, or indifference toward confession and spiritual function, to criminal activity, to lascivious activities, to asceticism.
Mischief is a broad spectrum of non-spiritual function and/or thinking.
He sets himself, refers to the pattern of life in which the person establishes themselves. For example a king sets himself up in power, or a criminal sets himself in crime, or a person sets themselves in habitual drinking.
And so the wicked person establishes themselves in the pattern of thinking and activity, which is contrary to the spiritual life.
And what they pursue is not good. Meaning they pursue the false or the lies of life, rather than the good or truth.
Legitimate good is correctly defined as, anything done while in fellowship.
If you are out of fellowship, then anything you do, is not good. The difference being, that in fellowship, anything done is within the sphere of Gods will. While when out of fellowship, then anything done is not in Gods will.
They do not reject evil, means just that.
Evil is anything and everything that exists outside of the divine sphere of the spiritual life.
And to reject evil means to confess and get into fellowship. So, when evil is not rejected, then the expectations of the spiritual life are ignored. So you do not confess, or you do not study, or you could care less about God or the Bible, or morals, and so forth. Whatever it is that you appear to be doing, spirit-wise, is mere pretense.
These things are not spontaneous things. People make conscious decisions either for or against the spiritual life. And, they make them over and over, again and again, day after day, throughout their life. Which simply means that no one has any excuse for making the mistake of evil, because evil is chosen, not accidental.