《新唐书·列传·卷二十九》
服役的工匠和没收进官府的奴隶都是违犯法律禁令逃亡在外的人，他们带着钳子凿子锤子木棒，来往进出，监门、宿卫、直长、千牛等警卫人员不能盘问。
丁匠官奴皆犯法亡命，钳凿槌杵，往来出入，监门、宿卫、直长、千牛不得苛问。
The craftsmen who served and the slaves confiscated by officials were all people who violated the law and fled, and they carried chisels, adzes, hammers, and wooden sticks, coming and going, and the guards at the gate, the guards at the inn, the prefects, and the thousand bulls could not question them.