Passage
{[A Psalm] of David.} Fret not thyself because of evil-doers, and be not envious of them that work unrighteousness;
{[A Psalm] of David.} Fret not thyself because of evil-doers, and be not envious of them that work unrighteousness;
Psalms 37:1 {[A Psalm] of David.} Fret not thyself because of evil-doers, and be not envious of them that work unrighteousness;
Psalms 37:2 for they shall soon be cut down like the grass, and fade as the green herb.
Psalms 37:3 Confide in Jehovah, and do good; dwell in the land, and feed on faithfulness;
The verse centers on "psalm", "david", "fret", "thyself", "evil-doers", "envious", and "unrighteousness". It is saying that the verse draws attention to "psalm" and "david", so its meaning should be read from those terms before moving to application.
The next verse adds "for they shall soon be cut down...", so "psalm" and "david" should be read forward into that movement. In Psalms context, the local focus is worship, trust, the LORD's kingship, and covenant mercy.
A plain takeaway is to answer the verse's own emphasis on "psalm" and "david" with trust shaped by these words, not by a vague optimism outside the passage.