The word "sir" is a title used to address a man in a respectful way. It can be used with or without the person's name, for example "Sir, good morning" or "Good morning, sir".
The word "good morning" is a greeting that is used in the morning to wish someone a good day. It is considered to be a polite way to begin a conversation or interaction with someone.
When combined, the phrase "sir good morning" means that the speaker is respectfully greeting a man in the morning. It is a polite and formal way to begin a conversation or interaction, and can be used in a variety of settings.