do sth by the book

郑人买履

A man of the state of Zheng wanted to buy a pair of shoes.

从前，郑国有个人想买双鞋。

He measured his foot and put the measurement on a chair.

他量好了自己脚的尺码，把它放在了椅子上。

When he set out for the market，he forgot to bring it along.

可当他赶往市集时，却忘了带量好的尺码。

It was after he had found the pair he wanted that this occurred to him.

他要买鞋时，才想了起来。

“I forgot the measurement”， said he.

他说：“我忘带尺码了。”

He went home to get it. But when he returned， the market had closed and he did not get his shoes after all.

他回家去取量好的尺码。等他赶回来时，市集已经关了，他还是没能买到鞋。

“Why didn‘t you try on the shoes with your feet?” He was asked.

有人问：“为什么不用你自己的脚去试一试鞋子呢?”

“I’d rather trust the measurement than trust myself.”

他说：“我宁愿相信尺码也不相信我自己的脚。”

成语“郑人买履”形容了一个不折不扣“不知变通”的人，做人如果“一味只知道照本宣科”，那就会变得“墨守成规”，就像这个“买鞋的郑人”一样了。英文中“郑人买履”可以用“do sth by the book”来表达，意思就是“ 凡事都按照规章制度来办”，有时候引申开来意思就是“墨守陈规”了。

我们一起来看一个例句：

This is a private deal - we don‘t have to do everything by the book.

这是一桩私下的买卖，我们没必要都按规矩来做，这么死板。