《宋书·志·卷十四》
回答说： 甲广、乙卯是君王忌讳的闩子，不敢奏乐、现在知悼子还停柩在堂，这比甲子、乙卯那种忌讳的子还要严重。
曰： 子卯不乐，知悼子在堂，斯其为子卯也大矣。
He replied: Jia Guang and Yi Mao are unlucky days for a ruler, and so they are not used for music. Now Co’s coffin is still in the hall, which is even worse than the taboo of Jia Zi and Yi Mao. 