If thou hast done foolishly in lifting up thyself, or if thou hast thought evil, lay thine hand upon thy mouth. Surely the churning of milk bringeth forth butter, and the wringing of the nose bringeth forth blood: so the forcing of wrath bringeth forth strife.
The last two verses of Agur’s proverbs seem unrelated to what has preceded. If an individual, in their folly, left themselves up against God or think negatively about Him, they need to listen to the voice of wisdom and put their hand over their mouth. If they do not listen or act, they will suffer the consequences.