Quick answer
The wise keep something back and the fool gets through it. The verse is about reserves rather than income.
Read both lines
Three lines, and the first two build the picture slowly: treasure that is desirable, and oil, which was food, light, and currency all at once, sitting in a house. Nothing is said about how it got there, which is the point, because the verse is not about earning. It is about what remains. Then the third line arrives with a single verb, and the verb means to swallow. The fool does not lose the store or invest it badly; he consumes it, which takes no skill and leaves no trace. Three verses earlier the chapter said a man who loves wine and oil will not be rich, and this one shows the same oil in a house where somebody left it alone.
Related: Proverbs 21:17 · Proverbs 13:22 · Proverbs 6:6–8 · Proverbs 30:25
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.