This idiom warns against harming or criticizing those who provide for or support you, such as employers, benefactors, or allies. It emphasizes gratitude and loyalty, suggesting that attacking your benefactor is foolish and self-destructive, as it risks losing their aid. The phrase is used in personal, professional, or political contexts to caution against ingratitude or betrayal, often with a moralizing or admonishing tone, highlighting the consequences of disloyalty.

The phrase likely stems from ancient observations of animals, particularly dogs, which might bite their owners despite being fed. It appeared in English by the 18th century, with a 1711 *Spectator* essay by Joseph Addison using a similar metaphor: ‘Bite not the hand that gives thee bread.’ The modern form was cemented in the 19th century, reflecting hierarchical social structures where dependence on patrons was common. Edmund Burke’s writings and later Charles Dickens’ novels used it to critique ingratitude. Its spread in American English, especially during labor disputes, underscored tensions between workers and employers, ensuring its relevance in modern contexts.