Hadith: The Prophet (may Allah's peace and blessings be upon him) met him on one of the roads of Madīnah while he was in a state of major ritual impurity. He sneaked away from him and went to take a bath. The Prophet (may Allah's peace and blessings be upon him) noticed his absence, and when he came back, he said: "Where were you, Abu Hurayrah?" He said: O Messenger of Allah, you met me while I was in a state of major ritual impurity, and I disliked to sit with you in that state until I had performed ghusl. The Messenger of Allah (may Allah's peace and blessings be upon him) said: @"Glory be to Allah! The believer never becomes impure."

عَنْ أَبِي هُرَيْرَةَ رَضيَ اللهُ عنه:
أَنَّهُ لَقِيَهُ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ فِي طَرِيقٍ مِنْ طُرُقِ الْمَدِينَةِ وَهُوَ جُنُبٌ، فَانْسَلَّ فَذَهَبَ فَاغْتَسَلَ، فَتَفَقَّدَهُ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ، فَلَمَّا جَاءَهُ قَالَ: «أَيْنَ كُنْتَ يَا أَبَا هُرَيْرَةَ؟» قَالَ: يَا رَسُولَ اللهِ، لَقِيتَنِي وَأَنَا جُنُبٌ فَكَرِهْتُ أَنْ أُجَالِسَكَ حَتَّى أَغْتَسِلَ، فَقَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «سُبْحَانَ اللهِ، إِنَّ الْمُؤْمِنَ لَا يَنْجُسُ».
[صحيح] - [متفق عليه] - [صحيح مسلم: 371]

Abu Hurayrah (may Allah be pleased with him) reported:
The Prophet (may Allah's peace and blessings be upon him) met him on one of the roads of Madīnah while he was in a state of major ritual impurity. He sneaked away from him and went to take a bath. The Prophet (may Allah's peace and blessings be upon him) noticed his absence, and when he came back, he said: "Where were you, Abu Hurayrah?" He said: O Messenger of Allah, you met me while I was in a state of major ritual impurity, and I disliked to sit with you in that state until I had performed ghusl. The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Glory be to Allah! The believer never becomes impure."
[Authentic hadith] - [Narrated by Bukhari & Muslim] - [Sahih Muslim - 371]

Explanation

The Prophet (may Allah's peace and blessings be upon him) met Abu Hurayrah (may Allah be pleased with him) on one of the streets of Madīnah. Abu Hurayrah was in a state of Janābah (major ritual impurity). Out of his profound respect for the Prophet (may Allah's peace and blessings be upon him), he disliked sitting with him and conversing while in that state, believing himself to be impure. So he discreetly went away and performed Ghusl (ritual bath), then returned and sat down. The Prophet (may Allah's peace and blessings be upon him) asked him where he had gone. He informed him of his condition and that he had disliked sitting with him while in a state of impurity from Janābah. The Prophet (may Allah's peace and blessings be upon him) responded with surprise, saying: "Verily, the believer is pure and never becomes impure under any circumstance—whether alive or dead."

Benefits from the Hadith

1. Janābah only prevents one from praying, touching the Qur’an, and staying in the mosque. It does not prevent sitting with or meeting other Muslims, nor does it render the person impure.
2. The believer is pure, whether alive or dead.
3. Honoring the people of virtue, knowledge, and righteousness—and keeping their company in the best manner.
4. The legitimacy of a follower seeking permission from their leader before departing—for the Prophet (may Allah's peace and blessings be upon him) reproached Abu Hurayrah (may Allah be pleased with him) for leaving without his knowledge. Indeed, seeking permission is a sign of good manners.
5. Saying: Subānallāh (Glory be to Allah) upon astonishment.
6. The permissibility of a person speaking about private matters concerning themselves, when there is a legitimate benefit.
7. The disbeliever is impure, but his impurity is spiritual, stemming from the corruption of his beliefs.
8. An-Nawawi said: "This Hadīth also contains etiquettes, that when a scholar notices something from their student that they fear may contradict correct practice, they should inquire about it, explain the proper way, and clarify the ruling to them, and Allah knows best."