Imam Sadiq (peace be upon him): When the Prophet (peace be upon him and his family) was afflicted with the illness that led to his passing, the Ahl al-Bayt (peace be upon them) and the companions of the Prophet gathered around him and said: "O Messenger of Allah (peace be upon him and his family)! If something happens to you, to whom should we turn after you, and whom will you choose from among us?" He gave no answer and remained silent. On the second day they repeated their question and heard no reply. On the third day they again asked: "O Messenger of Allah (peace be upon him and his family)! If something happens to you, to whom should we turn after you, and whom will you choose from among us?" The Prophet (peace be upon him and his family) said: "Tomorrow a star will descend from the sky into the house of one of my companions; so see who he is, for indeed he is my successor and the chosen one after me among you." There was no one present who did not wish that the Prophet (peace be upon him and his family) would say to him: "You are the successor after me." So when the fourth day arrived, each one sat in his own chamber awaiting the descent of the star. Then a star came down from the sky whose light overwhelmed the light of the world, and it settled in the room of Ali (peace be upon him). The people became angry and said: "By Allah, this man has gone astray and become rebellious, and he speaks about his cousin only out of caprice!" So Allah the Exalted revealed these verses regarding this: وَ النَّجْمِ إِذا هَوی* ما ضَلَّ صاحِبُکُمْ وَ ما غَوی* وَ ما یَنْطِقُ عَنِ الْهَوی* إِنْ هُوَ إِلَّا وَحْیٌ یُوحی [By the star when it descends, your companion (Muhammad) has never gone astray nor lost the way, and he never speaks out of desire! What he says is nothing but revelation sent down to him] ... .