God, in many verses of His Book, has emphasized the necessity of obeying His Prophet’s commandments, and for example has said: ﴿وَمَا أَرْسَلْنَا مِنْ رَسُولٍ إِلَّا لِيُطَاعَ بِإِذْنِ اللَّهِ﴾[1]; “And we have not revealed any prophet unless to be obeyed with the permission of God” and He has said: ﴿مَنْ يُطِعِ الرَّسُولَ فَقَدْ أَطَاعَ اللَّهَ ۖ وَمَنْ تَوَلَّى فَمَا أَرْسَلْنَاكَ عَلَيْهِمْ حَفِيظًا﴾[2]; “Anyone who obeys the Messenger, has obeyed God and anyone who turns away, We have not sent you over them as a guardian” and He has said: ﴿وَأَطِيعُوا اللَّهَ وَرَسُولَهُ إِنْ كُنْتُمْ مُؤْمِنِينَ﴾[3]; “Obey God and His Messenger, if you should be believers” and He has said: ﴿وَأَطِيعُوا اللَّهَ وَالرَّسُولَ لَعَلَّكُمْ تُرْحَمُونَ﴾[4]; “And obey God and the Messenger, that you may obtain mercy” and He has said: ﴿وَأَطِيعُوا الرَّسُولَ لَعَلَّكُمْ تُرْحَمُونَ﴾[5]; “And obey the Messenger, that you may obtain mercy” and He has said: ﴿فَلْيَحْذَرِ الَّذِينَ يُخَالِفُونَ عَنْ أَمْرِهِ أَنْ تُصِيبَهُمْ فِتْنَةٌ أَوْ يُصِيبَهُمْ عَذَابٌ أَلِيمٌ﴾[6]; “Therefore those who disobey from His law, must be afraid of sedition that may run into them or some painful punishment that run into them” and He has said: ﴿يَا أَيُّهَا الَّذِينَ آمَنُوا أَطِيعُوا اللَّهَ وَأَطِيعُوا الرَّسُولَ وَلَا تُبْطِلُوا أَعْمَالَكُمْ﴾[7]; “O you who have believed! Obey God and obey the Messenger and do not invalidate your deeds” and He has said: ﴿وَمَا آتَاكُمُ الرَّسُولُ فَخُذُوهُ وَمَا نَهَاكُمْ عَنْهُ فَانْتَهُوا ۚ وَاتَّقُوا اللَّهَ ۖ إِنَّ اللَّهَ شَدِيدُ الْعِقَابِ﴾[8]; “And take what the prophet gave you and abandon what the prophet prohibited you from that, and be afraid of God; since He has a severe punishment” and He has said: ﴿لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ أُسْوَةٌ حَسَنَةٌ لِمَنْ كَانَ يَرْجُو اللَّهَ وَالْيَوْمَ الْآخِرَ وَذَكَرَ اللَّهَ كَثِيرًا﴾[9]; “Undoubtedly there is a good example for you, in the prophet for every person who is hopeful of God and the last day and remembers God very much” and has said: ﴿وَمَا كَانَ لِمُؤْمِنٍ وَلَا مُؤْمِنَةٍ إِذَا قَضَى اللَّهُ وَرَسُولُهُ أَمْرًا أَنْ يَكُونَ لَهُمُ الْخِيَرَةُ مِنْ أَمْرِهِمْ ۗ وَمَنْ يَعْصِ اللَّهَ وَرَسُولَهُ فَقَدْ ضَلَّ ضَلَالًا مُبِينًا﴾[10]; “And no faithful man or woman should have the authorization to choose, when their God and the Prophet have issued a command and anyone who disobeys God and His prophet, has been misguided evidently”. With this description, it is clear that practicing what the Prophet has commanded and quitting what the Prophet has forbidden, are obligatory and their obligation is considered to be from the necessities of Islam, regardless of whether it has been or has not been exactly mentioned in the Book of God; because His Excellency’s command and interdiction definitely are not in conflict with the Book of God, rather by the permission of God, are the explainer of it; as God has said: ﴿وَأَنْزَلْنَا إِلَيْكَ الذِّكْرَ لِتُبَيِّنَ لِلنَّاسِ مَا نُزِّلَ إِلَيْهِمْ وَلَعَلَّهُمْ يَتَفَكَّرُونَ﴾[11]; “And we have revealed the Quran to you, in order to explain for people what was revealed to them and may they ponder”; for example, God has revealed the command of doing prayer generally in the Quran, so that His Prophet will explain its manner to the people in detail. Yes, His Excellency, in addition to being the reciter of the Book of God for the people, also teaches it to them and teaches wisdom to them and purifies them, which inevitably happens through his Sunnah; as God has said in this regard: ﴿لَقَدْ مَنَّ اللَّهُ عَلَى الْمُؤْمِنِينَ إِذْ بَعَثَ فِيهِمْ رَسُولًا مِنْ أَنْفُسِهِمْ يَتْلُو عَلَيْهِمْ آيَاتِهِ وَيُزَكِّيهِمْ وَيُعَلِّمُهُمُ الْكِتَابَ وَالْحِكْمَةَ وَإِنْ كَانُوا مِنْ قَبْلُ لَفِي ضَلَالٍ مُبِينٍ﴾[12]; “Indeed God bestowed a favor upon the believers by rising a Messenger from among themselves, who recites to them His messages, and purifies and teaches them the Book and wisdom, whereas before that they were clearly in error”; Considering that “wisdom” is mentioned after “the Book” and “purifying people and teaching them the Book” is mentioned after “reciting the verses of God to them”, which appears to be the difference and opposition between these two, and explains the concept of “Quran” and “Sunnah”. It is hereby understood that Quran explicitly invokes the Sunnah of the Prophet peace be upon him and his family and guides to its authority, and therefore, those who regard the Quran as proof, must inevitably accept the authority of the Prophet’s peace be upon him and his family Sunnah; because lack of faith in the authority of the Prophet’s peace be upon him and his family Sunnah, is a rebellion against Quran.

But it is natural that the necessity of obeying the Prophet’s peace be upon him and his family orders and prohibitions is based on being certain about it; regarding that having conjecture about it, based on the principle of ﴿إِنَّ الظَّنَّ لَا يُغْنِي مِنَ الْحَقِّ شَيْئًا﴾[13][14] is not considered sufficient, and having certainty about it is inherently and naturally proof, and therefore anyone who finds certainty about His Excellency’s commands and prohibitions, it is obligatory for him/her to obey them, and certainty about them can be achieved in two ways: to hear it from His Excellency for someone who is present near him or to hear the news of it from a large number of people who their collusion on lying and agreement on error is not reasonably possible, and this is the meaning of the words of God that He has said: ﴿إِنَّ فِي ذَلِكَ لَذِكْرَى لِمَنْ كَانَ لَهُ قَلْبٌ أَوْ أَلْقَى السَّمْعَ وَهُوَ شَهِيدٌ﴾[15]; “Indeed, there is a source of reminder in it for every person who has intellect or listens while he is present”; considering that the authority of Mutawatir news from His Excellency is rational and the authority of hearing from His Excellency is only for someone who listens to him while he is present. However, it should be noted that this word of God is guidance to a rational law; because the authority of Mutawatir news has a rational nature; meaning that intellect, with regards to the plurality and harmony of its narrators, does not give the possibility of its falsehood or wrongness, and gains certainty about its validity; as it does the same about Quran’s words and accepts their authenticity with regards to them being narrated from the Prophet in the form of Mutawatir, and considers them certain.

As a conclusion, whenever there is certainty that the Sunnah of the Prophet peace be upon him and his family, based on sensory or intellectual means, is issued by him, it is proof and accordingly can be the basis of the beliefs and actions of the Muslims as the explainer of general principles of Quran; as for example, the number of Rak’ats of the prayer and its essentials, have not been explained in the Quran in detail, but in a Mutawatir form have been narrated from the Prophet peace be upon him and his family and therefore, acting according to it is obligatory for Muslims and at the same time, is considered acting according to Quran; because Quran has obliged us to act according to the Prophet’s peace be upon him and his family Sunnah if it is certain, and this is a moderation extent that whoever has surpassed it or fallen behind it, has become misguided, and its surpassing means believing in the authority of Wahid and non-certain narrations from the Prophet peace be upon him and his family, and falling behind it, means believing in the lack of authority of Mutawatir and certain narrations from His Excellency, and these two are examples of overdoing and underdoing, and on both sides have a corrupted and dangerous sequence.

In order to learn more about this subject, please see “Saying 39” from the Sayings of his honor Mansoor Hashemi Khorasani may God protect him.