《韩非子·观行》
西门豹性情急躁，所以佩带柔韧的皮带来时刻提醒自己要从容；董安于性情迟缓，所以佩带绷紧的弓弦来鞭策自己敏捷。
西门豹之性急，故佩韦以缓已；董安于之心缓，故佩弦以自急。
Hsi-mên Pao was by nature of a hasty temperament, and so he used a girdle to restrict himself, thus making himself more calm; Tung An-yü was by nature of a sluggish temperament, and so he bent a bow, thus making himself more diligent.