Rav — one of the founding figures of the Babylonian Talmud, third century CE — had a difficult wife. Whenever he asked her to cook a particular dish, she would prepare its opposite. He requested lentils; she served beans. He requested beans; she served lentils. He made peace with it and ate whatever arrived.
Their son, Rabbi Chiya, grew up watching this daily comedy. When he became old enough to deliver messages between his parents, he studied his mother's pattern and started quietly reversing every request his father made. Rav would ask for lentils, Chiya would tell his mother that Rav wanted beans, and the mother — predictably — would cook lentils. The kitchen became harmonious. Rav received exactly what he asked for, for the first time in years.
Rav was amazed. "Your mother has changed," he remarked one day. Chiya explained his trick — how he had been passing along the opposite of every request so that his mother's contrariness would land on the correct meal.
Rav looked at his son carefully. "My son," he said, "stop. Your intention is beautiful — you wanted peace in the house. But if you keep speaking the opposite of what you mean, even with the best motive, your mouth will learn to lie. And a mouth that practices falsehood for a good reason will eventually use it for a bad one. Stop now, while you still remember which was which."
Gaster's Exempla (1924), No. 411, from Rabbeinu Nissim's Hibbur Yafeh, ends there. Shalom bayit — peace in the home — is a high value in Jewish ethics. But not every route to it is kosher. A family that is kept calm by small lies is a family that has traded its future for its afternoon.