Imam ash Shafi’ee said in the Chapter of Knowledge from his book ‘ar Risalah’: someone said to me: ‘what is knowledge? And what is obligatory upon the people regarding knowledge?
Ash Shafi’ee said to him: ‘Knowledge is of two types: general knowledge which is impossible for the mature adult-whose intellect is sound-to be ignorant of.’ It was said: like what? Ash Shafi’ee responded:’ like the five daily prayers, the fact that Allah has made it obligatory upon the people to fast the Month of Ramadan and make Hajj for those who have ability to do so. Also to give the obligatory charity (Zakat), and that Allah prohibited them from committing fornication, killing, stealing, drinking alcohol. And all the other things which Allah has instructed the Muslims to understand, comprehend, and act upon. By sacrificing and giving from their selves, their wealth, and to avoid and stay away from the things which they were prohibited from...Then he mentioned the specific knowledge.’
Imam Abdullah ibn Ahmed ibn Hanbal said: I asked my father about what is obligatory upon the man to seek of knowledge, he replied: ‘He should know that in which he can establish the prayers and other affairs of his religion like the fasting and obligatory charity, he should definitely have knowledge of these things.’
Al Khateeb al Baghdaadi stated: ‘It is obligatory upon every single person to seek that which is necessary for him to know regarding the affairs which Allah has made obligatory upon him. All of this according to his ability and personal efforts. Every mature, intelligent Muslim, male or female, free or slave, is obliged to knowing the way to purify oneself, to pray, and to fast. It is necessary that every Muslim becomes familiar with this knowledge.
It is also obligatory upon every Muslim to know and distinguish between what is permissible and prohibited from amongst the foods, drinks, clothing, genitals, blood, money. It is not permissible for anyone to be ignorant of any of these things as Allah has made it obligatory upon them to take the necessary steps to learning these issues until they reach puberty and they are Muslims, or after they accept Islam and reach sexual maturity.
It is also mandatory upon the leaders and the Imams to teach the women all that has been mentioned.
It is also obligatory upon the Imam to assist the people in learning and arrange for them sittings in which the ignorant can learn. They should be given provisions from the community savings, and it is obligatory upon the scholars to teach the ignorant so that the laymen can distinguish between the truth and the falsehood.’ 
Al Salmaasee said: ‘As for the religion, than it is obligatory upon the person to know all that concerns him. All mature adults who have reached puberty, it is obligatory upon them to have knowledge of ‘taharah’ (purification), knowledge of the prayer and fasting and knowledge of what is permissible and impermissible to eat. It is also obligatory upon the wealthy person to have knowledge of ‘zakat’, and the one who possesses the ability to make ‘hajj’- to know the rituals of ‘hajj’. Whoever has desire to get married than it is obligatory upon him to know what is permissible regarding the concubines and marriage and what is prohibited and permissible. Similarly it is obligatory upon the ones involved in buying and selling to know what is permissible and prohibited from business transactions and contracts. It is also obligatory upon the governors and leaders to know the religious rulings, the politics of war and battling, the rulings pertaining to war, fighting and the spoils of war. It is also obligatory upon everyone to memorize ‘ummul Qur’an’ (surah al Fatihah) as the Prophet said:
‘There is no prayer except with the suratul Fatihah’ , and memorize something from the Qur’an.’
Furthermore, it has been made obligatory upon some-fard kifayah-(collective duty)  to learn the ‘fiqh’ rulings and legislations while expanding and increasing in their knowledge until they have the ability to guide the people and give religious verdicts. So that they may provide answers for their incidents, issues, situations and calamities, as was mentioned previously in Allah’s statement:
“And it is not proper for the believers to go out to fight all together. Of every group of them, a party should go out, that they who are left behind may be taught their religion, and that they may warn their people when they return to them, so that they may beware of evil.” (Surah At-Tawbah, 9:122)
Ibn Kathir said: ‘Allah says that at least a group from every district or neighborhood and a group of people from every tribe should go out for fighting if all of them do not go. This is so that those who went with the Messenger would gain instruction and at the same time would learn from the divine revelation that was being descended upon the Prophet. Then they would warn their people about that battle and the enemies when they returned to them. So the group that went with the Prophet would achieve two goals (fighting with the Prophet and learning their religion from him at the same time). After the time of Prophet there should always remain and exist a group from every tribe or neighborhood who should seek religious knowledge or fight for the sake of Allah, for verily fighting is required from at least one group of people from every Muslim community. The verse preceding this one mentioned the obligation of fighting with the Prophet Muhammad if he went out to battle.’
This is what Sufyaan ibn Uyaynah meant when he explained the Prophet’s statement: ‘Seeking knowledge is obligatory’.
On the authority of Mujahid ibn Musa who said: ‘We were with ibn Uyaynah and this (above) hadeeth was mentioned, Ibn Uyaynah said: ‘It is not obligatory upon every Muslim, if some of them seek knowledge than it is sufficient for all. Like the funeral prayer, if some of them perform it than that is sufficient for all, or something similar to that.
Al Khateeb al Baghdaadi mentioned this narration and commented on it saying: ‘What was intended by Ibn Uyaynah was: the knowledge of the ‘fiqh’ rulings that are related to the subsidiary issues in the religion. As for the fundamentals, which are: knowledge of Allah, His ‘tawheed’, His attributes, the truthfulness of His Messengers - all of these things are from amongst the things which are obligatory upon everyone to have knowledge of, and it is not correct for anyone to act or believe on someone’s behalf regarding these issues.’
Ibn Abdul Barr said: ‘The scholars have come to consensus that there is some knowledge which is obligatory upon every single Muslim to know (fard-ayn), and other knowledge which is ‘fard kifayah’-if some of them perform it than it is no longer obligatory upon the others.’
In light of this, it is obligatory upon the scholars of Islam to teach the general population of Muslims as well as the students of knowledge. As for the general masses, than the scholar should summarize for them the issues of creed, the pillars of Islam, and the manners with which a Muslim should live his life, while knowing his Lord, his religion and his Prophet .
 Ar Risalah pg. 357-358 and the proceeding pages
 ‘Masaa’il Abdullah ibn Ahmed pg. 439
 Look al Faqeeh wal Mutafiqih 1/43-46
 (TN) He is Muhammad ibn Hibatullah ibn Abdullah as Salmaasee the Shafi’ee jurist. He died in the year 574 hijri
 This wording has been narrated by al Bukhari in ‘al Qiraa’ah khalf al Imam’ #55 on the authority of Ubadah ibn as Saamit. The wording which the six is mentioned in the six books of hadeeth is (لا صلاة لمن لم يقرأ بفاتحة الكتاب) . See Saheeh Bukhari #756, Muslim #394, Abu Dawud #822, at Tirmidhi #247, An-Nisaa’ee 2/137 Book of ‘Iftiitaah, Chapter: Obligation of reading al Fatihah in the prayer, Ibn Majah #837.
 ‘Manaazil al a’Imatul Arba’ah pg.134-135
 (TN) If some of the Muslims perform it than it is sufficient and it becomes desirable for the rest of the Muslims
 Tafsir ibn Kathir 2/543
 Al Faqeeh wal Mutafaqih pg. 44-45
 (TN) He is Abu Umar Yusuf ibn Abdullah ibn Muhammad ibn Abul Barr, the Spainard, al Maliki. The great historian and author of many great and important compilations. He was a judge, muhaddith, and jurist. He was born 368 hijri and died 463 hijri. He was known to follow the ‘Thahiree’ madth’hab, then he started following the Maliki madth’hab. He was a great and noble Imam and a scholar from Ahl Sunnah. He has many works from them: Al-Tamhid lima fil-Muwatta' min al-Ma`ani wal-Asanid ("The Facilitation to the Meanings and Chains of Transmission Found in Malik's Muwatta'"), Al-Istidhkar li Madhhab `Ulama' al-Amsar fima Tadammanahu al-Muwatta' min Ma`ani al-Ra'i wal-Athar ("The Memorization of the Doctrine of the Scholars of the World Concerning the Juridical Opinions and the Narrations Found in Malik's Muwatta'"); Jami` Bayan al-`Ilmi wa-Fadlihi wama Yanbaghi fi Riwayatihi wa Hamlih ("Compendium Exposing the Nature of Knowledge and Its Immense Merit, and What is Required in the Process of Narrating it and Conveying it") and many others.
 Jami’ Bayaan al Ilm wa Fadlihi 1/10
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