《后汉书·列传·宦者列传》
未到，十一月二日，孙程就与王康等十八人在西钟下集合谋划，都截单衣立誓。
未及至，十一月二日，程遂与王康等十八人，聚谋于西钟下，皆戴单衣为誓。
Before coming, on the 2nd of November, Sun Cheng and Wang Kang gathered with eighteen others at Xizhong to plan. They all cut single clothes and swore an oath.