泾水清，渭水浊。用以比喻事物和人品的差别。
出处：沈砺《咏史》；“渭浊泾清本异流，当涂符谶趁时收。”
用法：作宾语、定语；用于比喻句。
英语 The difference is as distinct as that between night and day.
