《礼记·曾子问》
既然不能做到，那么还是规定个时限为好。所以君子错过了祭祀的时间就不再补行，这是合乎礼的。 曾子问道： 国君死，灵枢已经停在殡宫，这时候臣子忽然得知父母突然去世，该怎么办？ 
曾子问曰： 君薨，既殡，而臣有父母之丧，则如之何？ 
Since it cannot be done, then it is better to set a time limit. Therefore, it is in accordance with ritual for a gentleman to not hold a make-up sacrifice if he misses the time for the offering. Zengzi asked: “When the monarch dies and the coffin is already in the funerary palace, if the subject suddenly learns that his parents have died, what should he do?” 