practice what (one) preaches

To do the things or behave the way that one advises, dictates, or espouses. My parents always told us to respect each other and not to bicker, and they really did practice what they preached. If you're going to tell your employees not to incur excessive, unnecessary costs, then you had better practice what you preach.

practise what you preach

COMMON If you practise what you preach, you behave in the way that you encourage other people to behave. Note: The verb `practise' is spelled `practice' in American English. He practised what he preached, being more interested in moral values than money. I ought to be showing leadership and practise what I am preaching. Note: People sometimes vary this expression. The Bishop said the government had let the people down badly: it had preached love but practised hate.

practise what you preach

do what you advise others to do.

ˌpractise what you ˈpreach

(saying) live or act the way you advise others to live or act: He’s always telling me to go on a diet, but he doesn’t practise what he preaches. He needs to lose weight too!