笑比河清

[成语]
xiào bǐ hé qīng

[含义]
形容态度严肃，难见笑容。

[来源]
《宋史·包拯传》：“立朝刚毅，贵戚宦官为之敛手，闻者皆惮之。人以包拯笑比黄河清。”

[用法]
偏正式；作谓语、宾语、补语；形容态度严肃


[英文]
to make one smile is as difficult as to purify the river