五十步笑百步：战国时候，孟子跟梁惠王谈话，打了一个比方，有两个兵士在前线上败下来，一个退了五十步，另一个退了一百步。退了五十步的就讥笑退了一百步的，说他不中用。其实两个人都是在退却，只是跑得远近不同罢了。（见于《孟子·梁惠王上》）
The pot calls the kettle black. According to Mencius·Duke Hui of Liang (I), during the Warring States Period, Mencius told Duke Hui of Liang a story by way of analogy, saying that two soldiers were defeated at the battlefront and retreated, one by fifty paces and the other a hundred paces. The one who retreated fifty paces laughed at the other who retreated a hundred paces, saying that the latter was no good. As a matter of fact, Mencius concluded, they both retreated, the mere difference being only the distance.
（比喻）自己跟别人有同样的缺点或错误，只是程度上轻一些，却讥笑别人
One who has the same shortcomings or mistakes as another, but to a lesser degree, laughs at the other
