Matthew Henry Commentary Proverbs 23:17-18

"Let not thy heart envy sinners; But [be thou] in the fear of Jehovah all the day long: For surely there is a reward; And thy hope shall not be cut off." — Proverbs 23:17-18 (ASV)

The believer's expectation shall not be disappointed; the end of his trials and of the sinner's prosperity is at hand.