《韩非子·难三》
现在于思不把庞子的过错告知穆公，穆公却尊重他；厉伯把庞子的过错告知穆公，穆公却鄙视他。
今子思不以过闻而穆公贵之，厉伯以奸闻而穆公贱之。
Currently, Yu Si did not tell Duke Mu about Pang Zi's misdeeds, but Duke Mu respects him; Li Bo told Duke Mu about Pang Zi's misdeeds, but Duke Mu despises him.