Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Q: What is the idiom for a situation that 'If people-in-authority don't follow their own set rules, then what can one expect from rest of us' in similar examples given below in different settings: When HR themselves are tardy, undisciplined then what can you expect from the employees (punctuality and discipline)? When traffic police themselves are offending (driving without belts, smoking while driving) what can you expect from the vehicle driving community in the city? When parents themselves are undisciplined (smoking in front of children), what can you expect from the children themselves? When the management is insincere, what can you expect from their staff?.
A: 
Do as I say, not as I do Model yourself after my instructions, not my actions. The phrase implies that the speaker is imperfect and makes mistakes, so one should follow their advice but not imitate them.My dad, a big smoker, always told me not to smoke. 'Do as I say, not as I do,' he used to say. Better quote: Prov.Take my advice, even though I am acting contrary to it. (Sometimes used as an apology for behaving hypocritically.)Jill: Why are you walking on the grass when I told you not to? Jane: But you're walking on the grass. Jill: Do as I say, not as I do. free dictionary Generally, in British English, this is always used from either a superior point of view, as a reply to a comment about how the figure of authority is doing something they've told people not to do... Or it's used as a pejorative term from those below the person who is 'doing', often with sarcasm: So it's a case of 'Do as I say, not as I do' then is it?