Answer a fool in simple terms so he doesn’t get a swelled head.
Answer a fool according to his folly, Lest he be wise in his own conceit.
Answer a [self-confident] fool according to his folly, lest he be wise in his own eyes and conceit. [Matt. 16:1-4; 21:24-27.]
Answer fools according to their folly, or they will deem themselves wise.
Respond to the foolish according to his folly, lest he imagine himself to be wise.
Answer a fool according to his folly, lest he imagine himself to be wise.