Practice what you preach is an idiom. We will examine the meaning of the common idiom practice what your preach, where it came from, and some examples of its idiomatic usage in sentences.
Practice what you preach is an admonishment to behave in the same manner that you expect others to behave or to do the things that you advise others to do. Someone who does not practice what he preaches is usually considered a hypocrite. The expression practice what you preach has been in use since the 1600s; the sentiment is found in the Bible. The phrase appears in the King James Version of the Bible, Matthew 23:3: “…they preach but do not practice.”
Example
It all just comes back to trying to practice what you preach, failing, and trying again, and the record reflects that. (Guitar Girl Magazine)
Practice what you preach – be a good role model and teach children about the possible dangers. (Connaught Telegraph)
The Good Morning Britain host urged the royal to “practice what you preach” after he told the world to be “like raindrops” in order to “relieve the parched ground”. (The Sun)