《宋史·列传·卷七十二》
即使不得已要动用武力，那么应当以理由充足和无理来作为胜负，这不是出使的臣下所能知道的。 契丹主说： 你不要固执，古代也有过这种事情。 富弼说： 自古以来只有唐高祖向突厥借用军队，当时赠送东西，或许称作献纳。
或不得已至于用兵，则当以曲直为胜负，非使臣之所知也。 契丹主曰： 卿勿固执，古亦有之。 弼曰： 自古唯唐高祖借兵于突厥，当时赠遗，或称献纳。
Even if we have to use force, we should use an ample and unreasonable request as our excuse for victory. This is not something a diplomat can know about. The Khitan emperor said: Don’t be so stubborn. This sort of thing has happened before in ancient times. Fu Bi said: In all of ancient times, only the Tang emperor Gaozu borrowed soldiers from the Turks. At that time, he did indeed use the word “offer” when giving them things.