《北史·列传·卷十七》
至于像援引同流的说法，贪图荣誉以求晋级的请求，如果不用条件加以限制，任其随意大开方便之门的话，以后就像蔓草滋生蔓延，难以铲除了。小小细流积成大河，就会破坏规章制度，挠乱国家大典，因此我认为应当明令加以禁止，以保证形成良好的风气。 
至如援流引比之诉，贪荣求级之请。如不限以关键，肆其傍通，则蔓草难除，涓流遂积，秽我彝章，挠兹大典，谓宜明加禁断，以全至化。
As for the request to cite the claim of the same Liu, who is greedy for honor in order to seek promotion, if the conditions are not restricted and the door of convenience is arbitrarily opened, it will be like the spread of weeds in the future, and it will be difficult to eradicate. A small trickle of water accumulates into a big river, which will destroy the rules and regulations and disrupt the national ceremony, so I believe that it should be explicitly prohibited in order to ensure a good atmosphere.