Quick answer
The righteous mouth is fruitful ground; wisdom grows out of it season after season. The perverse tongue gets the fate of a barren plant: cut down.
Read both lines
"Brings forth" is growth language, what fertile ground does: the righteous mouth produces wisdom the way good soil produces harvest, because of what is alive underneath. This completes the chapter's run of images for righteous speech: a well (10:11), silver (10:20), bread (10:21), now a living plant that keeps bearing. The perverse tongue, the twisting tongue, gets the other agricultural verdict: "cut out," felled like a tree bearing nothing anyone can eat. The passive verb leaves the axe in unnamed hands, but after 10:29 the reader knows whose government is at work.
Related: Proverbs 12:19 · Proverbs 15:4
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.