《战国策·魏一·苏秦拘于魏》
有齐国的帮助而得到宋国的土地对秦国并非不利，然而秦国之所以没有采纳齐国的请求，是不相信齐王和苏秦。
夫秦非不利有齐而得宋地也，然其所以不受者，不信齐王与苏秦也。
With Qi's help to gain Song State's land is not bad for Qin State, however, the reason why Qin State did not implement Qi's request was that it did not trust the King of Qi and Su Qin.