Part of the four things too wonderful, Proverbs 30:18–20, and disputed as an addition to it.
Quick answer
A fifth way, and the tone changes. Not a wonder now but a picture of someone who has done something and feels nothing, described with the plainness of a person finishing a meal.
Read the whole unit
Four things that leave no trace, and then this: someone who assumes the same is true of her.
Read the whole unit
The chapter's second numerical saying, and the only one whose subject is Agur's own bafflement. He is not listing things that are impressive. He is listing four things he cannot work out, and the word he uses, נִפְלְאוּ, is the word for something beyond a person rather than something beyond belief.
What the four share is that they leave nothing behind. An eagle crosses the sky and the sky closes. A snake crosses bare rock and there is no track. A ship crosses open water, and the Hebrew says it goes through the heart of the sea, which the NKJV footnotes; the wake heals. Then the fourth, a man with a young woman, and the saying stops there without explaining itself. After three pictures of a path that vanishes, the fourth is about two people, and it is filed under wonder, not under warning.
Then verse 20 uses the same word, way, for something else entirely. A woman commits adultery, eats, wipes her mouth, and says she has done nothing wrong. Whether that verse was originally part of the saying is genuinely disputed, and the catalog treats it as part of the unit while noting the dispute. What connects it is the tracelessness. Three of the four wonders leave no mark, and here is someone counting on that.
And that is where the unit joins the rest of the chapter. "I have done no wickedness" is verse 12 again in a different mouth: pure in its own eyes, and not washed. The chapter's real subject keeps turning out to be the person who has acquitted themselves.
What this verse contributes
The turn, and its restraint. The shock is not the adultery. The shock is the napkin. She eats, wipes her mouth, and speaks, and the sentence gives all three the same weight, which is the point: it was that ordinary to her. Then the words themselves, I have done no wickedness, and they are not a lie told to somebody. There is no one else in the verse.
This is verse 12 wearing different clothes. There the generation was pure in its own eyes and not washed from its filth; here the mouth is wiped and the conscience reports clean. The chapter has now said twice that the most durable human problem is not the wrong done but the ease of acquitting yourself of it.
What it does not mean
This is not a verse about women, and it must not be used as one. The book's warning chapters have a male reader in view throughout, and the male half of this act is standing just outside the frame at verse 19. The portrait is of a settled conscience, and settled consciences are not distributed by sex.
Nor is it a verse for identifying somebody. A person troubled enough by something they have done to wonder whether this describes them has already failed to match the description, since the whole picture is of someone untroubled.
Related: Proverbs 30:12 · Proverbs 20:9 · Proverbs 5:3–6
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.