يَا أَيُّهَا النَّبِيُّ حَسْبُكَ اللَّـهُ وَمَنِ اتَّبَعَكَ مِنَ الْمُؤْمِنِينَ
Yā ayyuhan-nabiyyu hasbukallāhu wa manit-taba‘aka minal-mu‘minīn
O Prophet! Sufficient for you is Allah and those of the faithful who follow you
(Sūrat al-Anfāl, No 8, Āyat 64)
This verse was sent to comfort the Prophet sallal-lāhu ‘alayhi wa-ālihi wasallam and remind him that he is not alone. Even when faced with enemies, Allah ‘azza wajall would help him and cause help to come for him from the believers who followed him. The verse reiterates the message given earlier: It is He who strengthened you with His help and with the means of the faithful (Q 8:62).
‘Allāmah Tabātabā’ī points out in Tafsīr al-Mīzān that Allah subhānahu wata‘ālā and the believers are not two separate sources of help. Nor are they one source in two parts. The purely Tawhīdī worldview which the Quran proclaims teaches that there can only be one Supreme cause. Everything stems from that single cause. Help is only from Allah and He causes a group of believers to help the Prophet. The help given to the Prophet by the believers is not independent of Allah (swt).
Some commentators say the verse was revealed when tribes that had a history of enmity with the Prophet came to him and offered their support. Allah warns the Prophet and reminds him that He and the believers are sufficient for him. He does not need those who harbor enmity for Allah and His mission. It is also a reminder about the contribution of the believers, through whom Allah (swt) kept His mission safe from the enemies. The verse also shows that not all the believers helped the Prophet, only those who followed him.
‘Allāmah Amīnī in his book al-Ghadir narrates from Hafiz Abū Na‘īm (a Sunni scholar) that this verse was revealed in praise of Imam Ali ‘alayhis-salām. The Prophet (s) received help from Imam Ali on many different occasions when facing the enemies. He relied on him at many crucial times for the Muslims. In Madinah the Prophet had to defend Islam and faced many battles. In each of these battles Imam Ali (a) was the hero. It was about Imam Ali that the Prophet said: There is no braver youth than Ali and no better sword than his Zulfiqar (Al-Tabarī, 2:514). It was about him that the Prophet said at the battle of Khaybar: Tomorrow I shall give the command (the standard) of this army to a man who is brave, who will keep on attacking, who will not run away from the battlefield, who loves Allah and His Prophet and is loved by Allah and His Prophet and who will not come back to me without success (Al-Hakim al-Naysapūrī, al-Mustadrak al-Sahīyayn, 4:356).
The Prophet knew that Allah helped him through the bravery and strength of Imam Ali (a). He said: Ali! Had I not been afraid that Muslims will start regarding you as the Christians regard the Christ, I would have said things about you which would have made the Muslims venerate you and to consider the dust of your feet as something worth venerating; but it will suffice to say that you are from me and I am from you; you will inherit me and I will inherit you; you are to me what Aaron was to Moses; you will fight for my cause; you will be nearest to me on the Day of Judgement; you will be next to me on the fountain of Kawthar; enmity against you is enmity against me; a war against you is a war against me; your friendship is my friendship; to be at peace with you is to be at peace with me; your flesh is my flesh; your blood is my blood; who will obey you will obey me. Truth is on your tongue, in your heart and in your mind. You have as much faith in Allah as I have. You are door to me. As per orders of Allah I give you these tidings that your supporters will be rewarded in Paradise and your enemies will be punished in Hell. (Ma‘ārijun Nubuwwah, 4:216; Sīrah ibn Hisham, p. 187)
As we celebrate Eid al-Ghadīr tonight let us remember that it commemorates the announcement of the authority of one who was foremost among the believers mentioned in this verse. Allah (swt) sufficed the Prophet by giving him the help of Imam Ali, and others.
Sources: Allāmah Muhammad Husayn Tabātabā’ī, Tafsīr al-Mīzān. Āyatullāh Nāsir Makārim Shirāzī (Ed.), Tafsīr-e Namūneh. Heroism of Imam Ali: https://www.imamali.net/?id=