《韩非子·外储说左上》
现在他知道君主不能长时间斋戒去观看那件没有用处的东西，所以就定了三个月的期限。
今知王不能久斋以观无用之器也，故以三月为期。
Now that he knows that the ruler cannot fast for that long so as to view that useless object, he has therefore set the time limit at three months.