Hadith: I advise you to fear Allah, and to listen and obey even if a slave is appointed as your leader. Whosoever among you shall live after me will see much discord. So hold fast to my Sunnah and the Sunnah of the Rightly-Guided Caliphs

عَنْ أَبِي نَجِيحٍ العِرْبَاضِ بْنِ سَارِيَةَ رضي الله عنه قَالَ: وَعَظَنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَوْعِظَةً وَجِلَتْ مِنْهَا القُلُوبُ، وَذَرَفَتْ مِنْهَا العُيُونُ، فَقُلْنَا: يَا رَسُولَ اللهِ! كَأَنَّهَا مَوْعِظَةُ مُوَدِّعٍ؛ فَأَوْصِنَا، قَالَ:
«أُوصِيكُمْ بِتَقْوَى اللَّهِ، وَالسَّمْعِ وَالطَّاعَةِ، وَإِنْ تَأَمَّرَ عَلَيْكُمْ عَبْدٌ، فَإِنَّهُ مَنْ يَعِشْ مِنْكُمْ بَعْدِي فَسَيَرَى اخْتِلَافًا كَثِيرًا، فَعَلَيْكُمْ بِسُنَّتِي وَسُنَّةِ الخُلَفَاءِ الرَّاشِدِينَ المَهْدِيينَ، عَضُّوا عَلَيْهَا بِالنَّوَاجِذِ، وَإِيَّاكُمْ وَمُحْدَثَاتِ الأُمُورِ؛ فَإِنَّ كُلَّ بِدْعَةٍ ضَلَالَةٌ».
[صحيح] - [رواه أبو داود والترمذي] - [الأربعون النووية: 28]

Abu Najīh al-‘Irbād ibn Sāriyah (may Allah be pleased with him) reported: The Messenger of Allah (ﷺ) gave us an exhortation at which hearts trembled and eyes shed tears. So we said: O Messenger of Allah, it is as though this is the exhortation of one bidding farewell; so advise us. He said:
"I advise you to fear Allah, and to listen and obey even if a slave is appointed as your leader. Whosoever among you shall live after me will see much discord. So hold fast to my Sunnah and the Sunnah of the Rightly-Guided Caliphs, and cling to them firmly. Beware of new things (in religion) because every religious innovation is a misguidance."
[Authentic hadith] - [Narrated by Abu Daoud & At-Termedhy] - [الأربعون النووية - 28]

Explanation

The Prophet (may Allah's peace and blessings be upon him) delivered an eloquent sermon that filled the Companions' hearts with fear and filled their eyes with tears. They said: O Messenger of Allah, it seems as if it is an admonition by one who will soon leave us - seeing his earnest effort in doing so. Hence, they asked him to give them advice that they would hold onto after him. He said: I advise you to fear Allah Almighty by carrying out duties and avoiding prohibitions. And to hear and obey, i.e., hear and obey the rulers, even if your ruler or the one who seized authority over you is a slave. In other words, if the most inferior among people became your ruler, you should not disdain to obey him, out of fear of turbulence and strife, for whoever lives from you after me will see a great discord. Then, he (may Allah's peace and blessings be upon him) clarified that the way out of this discord is by adhering firmly to his Sunnah and to the Sunnah of the rightly guided Caliphs after him, namely Abu Bakr as-Siddīq, ‘Umar ibn al-Khattāb, ‘Uthmān ibn ‘Affān, and ‘Ali ibn Abi Tālib (may Allah be pleased with them all), and by biting onto it with the molar teeth, i.e., by strictly observing and holding fast to the Sunnah. He (may Allah's peace and blessings be upon him) also warned them against the newly introduced matters in religion, as every religious innovation is a misguidance.

Benefits from the Hadith

1. The importance of following and adhering to the Sunnah.
2. Attention should be given to admonitions and softening of hearts.
3. The commandment to follow the four rightly guided Caliphs, namely Abu Bakr, ‘Umar, ‘Uthmān, and ‘Ali (may Allah be pleased with them all), after the Prophet.
4. The prohibition of introducing new things into the religion, and the fact that all religious innovations are misguidance.
5. Hearing and obeying whoever is in charge of the believers without disobeying Allah.
6. The importance of fearing Allah Almighty at all times and in all situations.
7. Discord will inevitably occur in this Ummah and when it occurs, Muslims must refer and adhere to the Sunnah of the Prophet (may Allah's peace and blessings be upon him) and to that of the rightly guided Caliphs.