Verses 18-21 express the same observation by expanding the thought of verse 17.

“A wicked man earns deceptive wages”: “A wicked man” renders the masculine singular adjective “wicked”. See the comment on “man” in verse 17. “Earns” translates the common Hebrew verb meaning to do or make. “Deceptive wages” refers to wages, rewards, or income that is different from what it appears to be. His wages are illusive, unreal, or worthless and so are not what the wicked had expected to get.

“But one who sows righteousness gets a sure reward”: “Sows righteousness” is a figure for doing good, living uprightly, or acting justly. “A sure reward” is literally “reward of truth,” meaning a genuine or certain reward. We may translate this verse, for example, “The wages of the wicked are an illusion, but the reward of the person who works for justice is real.”

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Proverbs. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .