折疑論 2.259

2.259

在昔夷齊不嗣。巢許無後（夷齊餓死於首陽。巢許隱跡於箕岫。皆無後嗣也）。

In the past, Boyi and Shuqi had no heirs, and Chaofu and Xu You had no descendants; (Boyi and Shuqi starved to death on Mount Shouyang; Chaofu and Xu You hid their traces on Mount Jishan; none of them had subsequent heirs.)