《史记·七十列传·匈奴列传》
努力耕田种桑而求得衣食满足，修筑城郭以保卫自己，所以百姓在急迫时不去练习攻战本领，在宽松时却又被劳作搞得很疲惫。唉！
夫力耕桑以求衣食，筑城郭以自备，故其民急则不习战功，缓则罢於作业。
Work hard to farm and grow mulberry trees in order to get enough clothes and food, and build city walls to protect themselves, so the people don't practice offense and war skills when they are in a hurry, and they are exhausted by work when they are relaxed. Alas!