Let not thine heart envy sinners: but be thou in the fear of the LORD all the day long.
Let not thine heart envy sinners - in prosperity, so as to be tempted to imitate their example (Psalms 37:1; Psalms 73:3).
But (be thou) (or, let thine heart be: from the first clause) in the fear of the Lord all the day long - the antidote to envy of the prosperity of sinners. "All the day long;" not by impulsive fits and starts; not following piety only so long as it is attended with worldly success, nor deserting it when thou seest difficulties in the way, and when prosperity seems to attend the wicked.