Allah تعالى says:
وَاعْتَصِمُوا بِحَبْلِ اللهِ جَمِيعًا وَلاَ تَفَرَّقُوا﴾ [آل عمران: 103].
The meaning of the verse:
﴾And hold fast, all of you together, to the Rope of Allâh (i.e. this Qur’ân), and be not divided among yourselves﴿ [Âl `Imrân (The Family of Imrân): 103].
Sheikh Al-Islâm Ibn Taymiyya said in Minhâj As-Sunna (5/134): “It [i.e. the Rope of Allah] is interpreted by: His Book, His religion, Islam, sincerity, His order, His covenant, obedience to Him and the Islamic community. All these interpretations are reported to be said by the Companions and those who follow them duly till the day of resurrection, and all of them are correct. In fact, the Quran orders to abide by Islam, which is the covenant of Allah, His order and obedience to Him; and holding fast altogether to the Rope of Allah is indeed to adhere to the community; and the reality of the religion of Islam is to vow sincerity to Allah”
All the different interpretations from Sahaba are available in Tafsir Ibn Abi Hatim Surah Imran, Ayat 103.
عَلِيٍّ، قالَ: سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ: «”كِتابُ اللَّهِ: هو حَبَلُ اللَّهِ المَتِينُ“»
Ali (رضي الله عنه) said ” The Book of Allah (Qur’an), is the solid rope of Allah.”
قالَ رَسُولَ اللَّهِ: الجَماعَةُ
The Messenger of Allah said: ” The main body of the muslims.” – Ibn Majah 3992
يا أيُّها النّاسُ عَلَيْكم بِالطّاعَةِ والجَماعَةِ، فَإنَّهُما حَبْلُ اللَّهِ الَّذِي أمَرَ بِهِ.
Ibn Masoud (may Allah be pleased with him) said: “ His Obedience and the congregation of the Muslims”.
الحَسَنِ في قَوْلِ اللَّهِ عَزَّ وجَلَّ: ﴿واعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا﴾ قالَ: بِطاعَتِهِ.
Al-Hasan Al Basri said: “His Obedience”
أبِي العالِيَةِ، في قَوْلِهِ: ﴿واعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا﴾ يَقُولُ: اعْتَصِمُوا بِالإخْلاصِ لِلَّهِ وحْدَهُ
Abū Al-‘Āliyah said: “Adhering with sincerity to Allah alone”
قَتادَةَ: ﴿واعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا﴾ قالَ: بِعَهْدِ اللَّهِ وبِأمْرِهِ
Qatadah ibn Di’ama said: “Allah’s covenant and his decree/orders”