This verse sits inside the aside on scoffers and the wise, Proverbs 9:7–12.
Quick answer
A claim about longevity, and it is an observation rather than a contract. Wisdom tends to keep people alive longer than folly does.
Read the whole unit
Six verses sit between the two banquets, and they are not obviously about either one. They are about who can be taught. Correct a scoffer and you collect insults; correct a wise man and he loves you for it. Give instruction to the wise and he gets wiser. Then the book's motto returns, and the section closes with a line about bearing your own outcome.
On the placement. Interpreters have long noticed that these verses interrupt the two-banquet structure, and some treat them as displaced or inserted. This catalog treats them as their own unit standing where they stand, and reading them in place, they do real work: between two invitations that sound identical, the book pauses to talk about what makes a person able to hear at all. The question the banquets pose is which voice you answer. The question this section poses is whether you are someone who can still be told anything.
On verses 7 and 8, which get misused. "Do not correct a scoffer" is not permission to avoid criticism, and it is not a label to hang on someone whose challenge you would rather not answer. The scoffer in this book is defined by a settled posture of contempt toward correction itself, not by disagreeing with you. Using this verse to dismiss a person is the single most common misreading, and it is self-serving in an obvious way, because the one thing a scoffer would most like is a verse that ends the conversation. Read honestly, verse 8's real force is in its second half: rebuke a wise man and he will love you. The test the section proposes is not whether you can identify scoffers. It is how you take being told you are wrong.
On verse 10. The book's motto returns here in a second form, and it closes Collection I where 1:7 opened it. What the fear of the LORD actually means is defined by the book itself at 8:13, and it is not dread: it is hating what is evil, an aversion to what harms rather than terror of God.
What this verse contributes
This verse states wisdom's yield in the plainest terms the book has, and the plainness is worth taking at face value before anything else is said. A person who avoids ruinous company, ruinous debt, and ruinous appetite generally lives longer than one who does not, and the previous eight chapters have been describing exactly those hazards. The claim is the book's normal genre: a description of how life usually runs under God's government, offered so a young man can see the shape of the road early.
What it does not mean
This is not a guarantee of a long life and cannot be read backward. Proverbs observes; it does not sign contracts, and a person who dies young has not failed at wisdom. The whole book knows better than that, saying elsewhere that time and chance touch everyone's plans and that the LORD takes up the cause of those who suffer wrongly. Read as a promise, this verse becomes cruel at the first funeral. Read as the book intends it, it is a plain statement that the road matters.
Related: Proverbs 3:1–2 · Proverbs 10:27 · Proverbs 16:9
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.