practise what you preach

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to do the things that you advise other people to do

言传身教，以身作则;言行一致

He's such a hypocrite! He never practises what he preaches. 他真是个伪君子!他从来都是言行不一。

You keep telling the children that their room is in a mess. Isn't it time you began to practise what you preach and tidied up the garage?

你老是对孩子们说他们的屋子太乱了，难道你不也该按自己的话去做，将车库搞得整洁一些?