Imam Baqir (peace be upon him)- Imam Sadiq (peace be upon him) said: My father Imam Baqir (peace be upon him) was performing tawaf of the Kaaba when suddenly a veiled man appeared, interrupted my father's tawaf and took him to a house beside Mount Safa ... and he said: "... O Abu Ja'far (peace be upon him)! If you wish, you inform me, and if you wish, I will inform you" ... My father said to him: "If you wish, I will inform you about that [verse]." He said: "Yes, I wish so." My father (peace be upon him) said: "If our Shia say to our opponents: 'Allah the Mighty and Majestic says to His Prophet (peace be upon him and his family): We sent down the Quran on the Night of Qadr ... Did the Messenger of Allah (peace be upon him and his family) receive new knowledge on the Night of Qadr which he did not know on other nights, or did Jibra'il (peace be upon him) not bring it to him on nights other than that?' The opponents will say: 'No.' Say to them: 'Did he have any option other than making that knowledge manifest?' They will say: 'No.' Say to them: 'Was there any contradiction in what the Prophet (peace be upon him and his family) made manifest from the knowledge of Allah, Mighty is His remembrance?' If they say: 'No,' say to them: 'Then someone who claims to rule by the ruling of Allah and yet contradictions and differences exist in his ruling — has he opposed the Messenger of Allah (peace be upon him and his family)?' They will say: 'Yes.' And if they say: 'No,' they have contradicted and invalidated their earlier statement [that whatever is from Allah contains no contradiction]. And say to them: The true interpretation of those mutashabih [ambiguous] verses is known only by Allah and those firmly rooted in knowledge. (Aal Imran/7). If they say: 'Who are those firmly rooted in knowledge?' Say: 'The one in whose knowledge there is no contradiction.' If they say: 'Who is he?' Say: 'The Messenger of Allah (peace be upon him and his family) possessed this knowledge; did he convey this knowledge to the people?' If they say: 'Yes, he conveyed it,' say: 'When he passed away, was there a successor in his place who possessed knowledge without contradiction?' If they say: 'No,' say: 'The successor of the Messenger of Allah (peace be upon him and his family) must be confirmed [by Allah], and the Messenger of Allah (peace be upon him and his family) would not make anyone his successor except one who rules by his ruling and is like him in every respect except in the station of prophethood. And if the Messenger of Allah (peace be upon him and his family) did not appoint any successor in his knowledge, [then it must be said that] he abandoned to their own devices those of his ummah who would be born after him.' If they say to you: 'The knowledge of the Messenger of Allah (peace be upon him and his family) was only from the Quran [which is still present among the ummah and to which they can refer],' [in reply] say: "حم وَ الْکِتابِ الْمُبِینِ إِنَّا أَنْزَلْناهُ فِی لَیْلَةٍ مُبارَکَةٍ إِنَّا کُنَّا مُنْذِرِینَ فِیها ... إِنَّا کُنَّا مُرْسِلِینَ [Ha Mim. By the clear Book. Indeed We sent it down on a blessed night; indeed We were warning therein ... indeed We were sending down]." If they say to you: 'Allah the Mighty and Majestic sends down this matter only upon a prophet,' [in reply] say: 'This matter which on the Night of Qadr is arranged according to wisdom — is it sent down from the angels and the Spirit from one heaven to another heaven, or from the heaven to the earth?' If they say: 'From one heaven to another heaven,' [this is not correct,] because there is no one in the heavens who turns from obedience to disobedience [so as to be in need of the divine command]. And if they say: 'From the heaven to the earth, and the people of the earth are more in need of this matter,' say: 'Then should not these people of the earth have a master and a greater one to whom they may go for judgment [and resolution of differences]?' If they say: 'The caliph is their ruler and judge,' [in reply] say: Allah is the guardian and protector of those who believe; He brings them out of the darknesses into the light. [But] those who disbelieved, their guardians are the tawaghit [false idols] who bring them out from the light into the darknesses; they are the people of the fire and will remain in it forever. (Baqarah/257). By my own life! There is no walī (guardian) of Allah, mighty is His remembrance, in the earth or the heaven except that he is confirmed [by Allah], and whoever is confirmed never errs; and there is no enemy of Allah, mighty is His remembrance, in the earth except that he is forsaken, and whoever is forsaken never attains the truth. Just as it is necessary that the command be sent down from the heaven so that the people of the earth may judge according to it, likewise it is necessary that a ruler [from Allah] be appointed. If they say: 'We have no knowledge of this matter,' say to them: 'Say whatever you wish, for Allah the Mighty and Majestic has never willed that after Muhammad (peace be upon him and his family) He should leave His servants without a proof [and an imam]' ... .