《魏书·帝纪·卷二》
晁崇回答说： 从前商纣王在甲子日灭亡，用兵的人忌讳这一天。 
对曰： 昔纣以甲子亡，兵家忌之。 
Chao Chong answered and said, "In the past, the Shang Dynasty King Zhou perished on the day of Jiazi, so people who fought on that day in the past considered it a taboo."