Imam Sadiq (peace be upon him): When Allah the Mighty and Majestic sent Muhammad (peace be upon him and his family), the later Mustahfizin (custodians) submitted to him, but the Children of Israel denied him. He called to Allah the Mighty and Majestic and strove in His path, until Allah the Exalted commanded him to make manifest the virtue of his successor. The Prophet (peace be upon him and his family) said: 'O Lord! The Arabs are a harsh people; there was no book among them, no prophet was sent to them, and they do not know the virtue and honour of the prophets (peace be upon them). If I tell them of the virtue of my Ahl al-Bayt, they will not believe.' So Allah the Exalted said: وَ لا تَحْزَنْ عَلَیْهِمْ [And do not grieve over them] (Nahl/127), وَ قُلْ سَلامٌ فَسَوْفَ یَعْلَمُونَ [And say: peace — soon they will know] (Zukhruf/89). The Prophet (peace be upon him and his family) mentioned a little of the virtue of his successor, and hypocrisy fell into their hearts. The Messenger of Allah (peace be upon him and his family) became aware of that hypocrisy and their words. Allah the Exalted said: 'O Muhammad (peace be upon him and his family)! وَ لَقَدْ نَعْلَمُ أَنَّکَ یَضِیقُ صَدْرُکَ بِما یَقُولُونَ [Indeed We know that your breast is straitened by what they say] (Hijr/97). فَإِنَّهُمْ لا یُکَذِّبُونَکَ وَ لکِنَّ الظَّالِمِینَ بِآیاتِ اللَّهِ یَجْحَدُونَ [They do not deny you, but the wrongdoers reject the signs of Allah] (Anam/33), meaning they reject without having any proof.' The Messenger of Allah (peace be upon him and his family) used to conciliate them and enlist some against others, and he continued to bring out for them something of the virtue of his successor, until this Surah (al-Inshirah) was revealed. When the Prophet (peace be upon him and his family) was informed of his death and the news of it was announced to him, he brought his argument against them. Allah the Exalted said: فَإِذا فَرَغْتَ فَانْصَبْ* وَ إِلی رَبِّکَ فَارْغَبْ [So when you are free, set up (your banner), and to your Lord turn (your desire)], meaning: when you are done [with delivering the message], set up your banner and sign (that is, Ali (peace be upon him)) and make your succession manifest. So the Prophet (peace be upon him and his family) [on the day of Ghadir] openly announced the virtue of Ali (peace be upon him) and said: 'Whoever I am his master, Ali (peace be upon him) is his master. O Allah, befriend whoever befriends him and be an enemy to whoever is his enemy' — three times. And again [at the Battle of Khaybar, after he had made several men bearers of the banner and they could not achieve victory] he said: 'Indeed I shall send a man who loves Allah and His Messenger, and Allah and His Messenger love him; he is no runaway.' By this statement the Prophet (peace be upon him and his family) alluded to the one who had turned back [from the gate of the fortress of Khaybar]. He considered his companions cowardly, and his companions considered him cowardly.