<P> "As a dog returns to his vomit, so a fool repeats his folly" is an aphorism which appears in the Book of Proverbs in the Bible--Proverbs 26: 11 (Hebrew: כְּ֭כֶלֶב שָׁ֣ב עַל ־ קֵאֹ֑ו כְּ֝סִ֗יל שֹׁונֶ֥ה בְאִוַּלְתֹּֽו ‎ ‎ Kəḵeleḇ šāḇ' al - qê'ōw; kəsîl, šōwneh ḇə'iwwaltōw .), also partially quoted in the New Testament, 2 Peter 2: 22 . It means that fools are stubbornly inflexible and this is illustrated with the repulsive simile of the dog that eats its vomit again, even though this may be poisonous . Dogs were considered unclean in Biblical times as they were commonly scavengers of the dead and they appear in the Bible as repugnant creatures, symbolising evil . The reference to vomit indicates excessive indulgence and so also symbolises revulsion . </P> <P> The incorrigible nature of fools is further emphasised in Proverbs 27: 22, "Though you grind a fool in a mortar, grinding them like grain with a pestle, you will not remove their folly from them ." </P> <P> In Proverbs, the "fool" represents a person lacking moral behavior or discipline, and the "wise" represents someone who behaves carefully and righteously . The modern association of these words with intellectual capacity is not in the original context . </P> <P> The Greek translation in the Septuagint developed the idea, imbuing it with a sense of shame and guilt, "As when a dog goes to his own vomit and becomes abominable, so is a fool who returns in his wickedness to his own sin ." This was due to the contemporary idea of the fool as ungodly . </P>

Bible verse like a dog returns to its vomit