Imam Baqir (peace be upon him): Indeed, if our Shia say to those who oppose us that Allah the Mighty and Majestic said to the Messenger of Allah (peace be upon him and his family): إِنَّا أَنْزَلْناهُ فِی لَیْلَةِ الْقَدْرِ [Indeed, We sent it down in the Night of Decree]... — did the Messenger of Allah (peace be upon him and his family) on this night receive any new knowledge that he did not know on other nights, or did Jibreel bring him anything on other nights? In answer to this question the opponents will say: No. Say to them: Was there any escape from the knowledge that the Prophet had being made known and shown? They will say: No. Say to them: One who claims to rule by the ruling of Allah while there is contradiction and disagreement in his rulings — is he opposing the Messenger of Allah? They will have no choice but to say: Yes; and if they say No, they have contradicted their own first statement. Say to them: ما یَعْلَمُ تَأْوِیلَهُ إِلَّا اللهُ وَ الرَّاسِخُونَ فِی الْعِلْمِ [None knows its interpretation (i.e. of the Quran and Allah's knowledge) except Allah and those firmly rooted in knowledge] (Aal Imran/7). If they ask: Who are those firmly rooted in knowledge? Say: The one in whose knowledge there is no disagreement. If they say: Who is he? Say: The Messenger of Allah (peace be upon him and his family) was the possessor of this knowledge; did he convey it and deliver it to the people, or not? If they say: He did convey and deliver it, say: When he passed away, was there a successor in his place who possessed knowledge free of disagreement? If they say: No, say: The successor of the Messenger of Allah must be one supported by Allah, and the Messenger of Allah (peace be upon him and his family) would not appoint as his successor anyone except one who rules by his ruling and is like himself, except in prophethood. And if the Messenger of Allah had not appointed a successor to hold his knowledge, he would have wasted all the people who were still in the loins of men and the generations yet to come. 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 exists among the ummah and to which they can cling], answer them: حم. وَ الْکِتابِ الْمُبِینِ. إِنَّا أَنْزَلْناهُ فِی لَیْلَةٍ مُبارَکَةٍ إِنَّا کُنَّا مُنْذِرِینَ [Ha Mim. By the clear Book. Indeed, We sent it down in a blessed night; indeed, We are ever warning] (Dukhan 3–1). If they say: Allah sends command only to the Prophet, say in reply: This wise affair which is distinguished and conveyed by the angels and the Spirit — do they descend from one heaven to another, or from the heaven to the earth? If they say: From one heaven to another — this is not correct, because in the heavens there is no one who sins or transgresses so as to need any ruling to be conveyed. And if they say: From the heaven to the earth, and the people of the earth are greatly in need of such a ruling — say: Do the people of the earth have any option but to have a chief and master to whom they may bring their disputes for judgement? If they say: The caliph of the time is their judge, say in reply: اللهُ وَلِیُّ الَّذِینَ آمَنُوا یُخْرِجُهُمْ مِنَ الظُّلُماتِ إِلَی النُّورِ [Allah is the Guardian of those who believe; He brings them out of darkness into light] — (but) those who disbelieved, their guardians are the tyrants, who bring them out of light into darkness; they are the people of the Fire, and they will remain in it forever (Baqarah/257). By my life, there is no friend of Allah, the Mighty in remembrance, on the earth or in the heavens who is not divinely supported, and whoever is supported does not err; and there is none on the earth who is an enemy of Allah, the Mighty in remembrance, but that he is forsaken, and whoever is forsaken and left to himself does not go straight. Just as every affair must inevitably descend from the heaven for the people of the earth to rule by it, likewise there must be a ruler and guardian. If they say: We do not know this one, say to them: Say whatever you wish — Allah the Mighty and Majestic has refused, after Muhammad (peace be upon him and his family), to leave His servants without a proof and an Imam over them.