Hadith: As for this man, he has disobeyed the Prophet (may Allah's peace and blessings be upon him)

عن أبي الشعثاء، قال: كنا قُعُودًا مع أبي هريرة رضي الله عنه في المسجد، فأذن المؤذن، فقام رجل من المسجد يمشي، فأَتْبَعَهُ أبو هريرة بَصَرَهُ حتى خرج من المسجد، فقال أبو هريرة: أما هذا فقد عصى أبا القاسم صلى الله عليه وسلم .
[صحيح] - [رواه مسلم]

Abu Ash-Sha‘thā' reported: As we were sitting in the mosque with Abu Hurayrah (may Allah be pleased with him) the Muezzin proclaimed the Adhān and then a man stood up in the mosque and started walking out. Abu Hurayrah followed him with his eyes until he went out of the mosque. Thereupon, Abu Hurayrah said: "As for this man, he has disobeyed the Prophet (may Allah’s peace and blessings be upon him)."
[Authentic hadith] - [Narrated by Muslim]

Explanation

Abu Ash-Sha‘thā' relates in this Hadīth that they were sitting with Abu Hurayrah (may Allah be pleased with him) in the mosque, and the Muezzin proclaimed the Adhān. Then, a man stood up and walked. Meanwhile, Abu Hurayrah kept looking at him to know whether he would leave the mosque or what. Then, when it became clear that the man was actually leaving, Abu Hurayrah (may Allah be pleased with him) stated that this act runs counter to the Prophet’s guidance.