1 The verb form is singular (see vv. 3–10 as well, where the second person verbs and pronouns are also singular). The psalmist’s exhortation has a wisdom flavor to it; it is personalized for each member of his audience.
2 Heb “over sinners.” The context indicates that the psalmist has in mind the apparent power and success of sinners. See v. 7b.
3 Heb “like green vegetation.”

In other versions

Of David.

Fret not yourself because of evildoers;

be not envious of wrongdoers!

For they will soon fade like the grass

and wither like the green herb.

Of David.

Do not fret because of those who are evil

or be envious of those who do wrong;

for like the grass they will soon wither,

like green plants they will soon die away.

Of David.

Do not be agitated by evildoers;

do not envy those who do wrong.

For they wither quickly like grass

and wilt like tender green plants.

A psalm of David.

Don’t worry about the wicked

or envy those who do wrong.

For like grass, they soon fade away.

Like spring flowers, they soon wither.

Of David.

Do not fret because of evildoers;

do not be envious of doers of wickedness.

For like the grass they will dry up quickly,

and like green vegetation they will wither.

A Psalm of David.

Fret not thyself because of evildoers,

Neither be thou envious against the workers of iniquity.

For they shall soon be cut down like the grass,

And wither as the green herb.

Public Domain