Quick answer
A righteous person's speech is a water source: people drink from it and live. The wicked mouth has violence where the water should be.
Read both lines
A well of life, in a dry land, is not a luxury; it is the reason a settlement exists. The sages claim that some people's ordinary speech, counsel, encouragement, truth-telling, functions in a community the way water functions in a landscape. You know these people; you may not have noticed that you always leave their kitchen less thirsty than you arrived. The second line repeats 10:6 word for word, and here the contrast sharpens it: where the righteous mouth pours out life, the wicked mouth conceals violence under its surface. It looks like a well too. What comes up out of it is the difference. Verses 11–21 form a loose run of speech proverbs, and this verse is the headwater.
Related: Proverbs 13:14 · Proverbs 18:4 · Proverbs 10:6
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.