《淮南子·说山训》
丢失了羊而得到了牛，那么就没有人不愿意丢失东西的了。断了手指而能保全性命，那么就没有人不愿意这样做的。
亡羊而得牛，则莫不利失也；断指而免头，则莫不利为也。
If losing a sheep could lead to gaining a cow, then no one would be unwilling to lose things. If losing a finger could lead to preserving one's life, then no one would be unwilling to do so.