《礼记·曲礼下》
国君如果没有缘故，佩玉不离身。大夫没有缘故，不撤除佩玉。读书人没有缘故，不撤除琴瑟。
君无故，玉不去身；大夫无故不彻县，士无故不彻琴瑟。
The sovereign never unbraces his gem unless he has occasion. An officer never lays aside his gem when he has no occasion. A 'scholar' never lays aside his lute or zither when he has no occasion.