Proverbs 26:9-11

Complete Jewish Bible

⁹ Like a thorn branch in the hand of a drunk
    is a proverb in the mouth of a fool.
¹⁰ A master can make anything,
    but hiring a fool is like hiring some passer-by.
¹¹ Just as a dog returns to his vomit,
    a fool repeats his folly.