question #1 Sahih Muslim 655b, Book 5, Hadith 323 : What is the significance of staying in the mosque after the call to prayer has been announced?

I heard it from Abu Huraira that he saw a person getting out of the mosque after the call to prayer had been announced. Upon this he remarked: This (man) disobeyed Abu’l-Qasim (ﷺ).