Quick answer
Wisdom inside gets recognized outside, and pleasant speech makes teaching land. "Sweetness of the lips" is not flattery; it is truth dressed for travel.
Read both lines
The first line moves from hidden to public: discernment eventually earns a reputation. The second adds the multiplier: the same truth, delivered harshly, bounces off its hearer; delivered with grace, it goes in and grows. The verse quietly indicts a common failure of right people: being correct in a tone that guarantees no one benefits. Wisdom includes the delivery, and the next verses extend the thought: the wise heart teaches its own mouth (16:23), and pleasant words are a honeycomb (16:24).
Related: Proverbs 25:11 · Colossians 4:6
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.