Don't be sweet, lest you be eaten up; don't be bitter, lest you be spewed out.

This saying circulates as a traditional Jewish proverb (often labeled “Yiddish” in English-language collections) and is typically presented as folk wisdom rather than a line traceable to a single author or fixed occasion. It belongs to a broader genre of ethical maxims used in communal instruction—advice about conduct in social and business life, where extremes of temperament can invite harm. In that setting, “sweetness” and “bitterness” function as vivid metaphors for overly accommodating versus overly harsh behavior, warning that each can provoke a predictable social response: exploitation on the one hand, rejection on the other.

The proverb advises balance: excessive sweetness (over-pleasing, naïveté, or lack of boundaries) can make a person easy to exploit—“eaten up.” Excessive bitterness (acerbity, cynicism, or cruelty) can make one socially intolerable—“spewed out.” Its force lies in pairing two vivid outcomes to show that opposite extremes converge in harm. Ethically, it promotes measured speech and conduct: kindness tempered by self-respect, and honesty tempered by tact. As practical wisdom, it recognizes that character is judged relationally; survival in community often depends on avoiding traits that either invite predation or provoke rejection.