Chapter: If The Adhan Is Called And You Are In The Mosque, Then Do Not Leave
It was narrated that Abu Sha'tha said: We were sitting in the mosque with Abu Hurairah when the Mu'adh-dhin called the Adhan. A man got up and walked out of the mosque, and Abu Hurairah followed him with his gaze until he left the mosque. Then Abu Hurairah said: This man has disobeyed Abul-Qasim.'
It was narrated that 'Uthman said: The Messenger of Allah said: 'Whoever hears the Adhan when he is in the mosque, then goes out and does not go out for any (legitimate) need and does not intend to return, is a hypocrite.'