The Sources of Tafseer
1. The Glorious Qur'an
The first source of the knowledge of tafsir is the Holy Qur'an itself. Accordingly, it happens very often that a certain point which is brief and requires explanation is invariably clarified by some other verse of the Qur'an itself. For instance, there appears that sentence of prayer in the Surah al-Fatihah: Arabic that is, 'Guide us in the straight path - the path of those on whom You have bestowed Your Grace...' Now it is not clear here as to who are those whom Allah Almighty has blessed. But, in another verse, they have been identified very clearly where it is said:
So, these are the people whom Allah Almighty has blessed, being the prophets, their true followers, the martyrs (in the way of Allah) and the righteous. (4:69)
Therefore, when respected commentators explain some verse, they first check to see if a tafsir of this verse is already there elsewhere in the noble Qur'an itself. If it is there, they elect to go by it as their first choice.
2. The Hadeeth
The words and the deeds of the Holy Prophet called Hadeeth, and as it has been stated earlier, Allah Almighty had sent him with the Qur'an solely for the purpose that he should explain to people, openly and explicitly, the correct meanings of the noble Qur'an. Consequently, he discharged this duty with grace and excellence both by his words and deeds. In fact his whole blessed life is, after all, a practical tafsir of Qur'an. It is for this reason that respected commentators, in order to understand the Qur'an, have laid the greatest emphasis on Hadeeh as the second source, and it is in the light of ahadeeth that they have determined the meanings of the Book of Allah. However, because all sorts of narrations - sound, weak, and fabricated - are included in Hadeeth, therefore research-oriented commentators do not accept a narration as trustworthy until it withstands the principles used in the scrutiny of Hadeeth narrations. Hence, finding a hadeeth report somewhere, looking at it, and then employing it to determine a certain tafsir is not correct, because that report could be weak, even contrary to other stronger reports. This is really a very delicate matter, and venturing therein is the exclusive prerogative of those who have spent their years in mastering these fields of knowledge.
3. The Reports from the Sahabah
The noble Sahabah (RA) (Companions), may Allah be pleased with them all, had received their education directly from the Holy Prophet . In addition to that, they were personally present on the scene when Wahy came, and they had themselves witnessed all circumstances and backgrounds of the revelation of the Qur'an. Therefore, naturally, the recorded statements of these blessed souls are far more authentic and trustworthy in explaining the noble Qur'an; the later people cannot take that place. Hence, in the case of verses the explanation of which is not found in the Qur'an or Hadeeth, statements recorded from the noble Companions (RA) are given the highest priority. Consequently, if there is a consensus of Companions on the explanation of a certain verse, the commentators follow just that, and explaining it in any way, other than that, is not permissible. By the way, if the statements of Companions (RA) differ in the interpretation (tafsir) of a certain verse, then the commentators who come later examine them in the light of arguments and determine as to which interpretation or explanation can be given preference. In order to handle this situation, there is an important corpus of rules and regulations already codified under the sciences of Usul al-Hadeeth and Usul al-Tafsir a detailed discussion of which is not appropriate here.
4. The Reports from the Tabi'in or Successors
After Companions (RA) (Sahabah) come the Successors (Tabi'in). The later are those who have learnt the tafsir of Qur'an from the Companions (RA). Therefore, their statements too have great importance in the science of tafsir, although there exists a difference among scholars whether or not the statements of the tabi'in are decisive in tafsir (al-ltqan, 2/179) but their importance is something which cannot be denied.
5. The Arabic Language
Since the noble Qur'an was revealed in the Arabic language, therefore, in order to explain the Qur'an, it is necessary to have a complete mastery over the language. There are several verses of the noble Qur'an in the background of which there happen to be just no attending circumstances of revelations, or any juristic or scholastic question, therefore, in their tafsir or explanation, the sayings of the Holy Prophet , or the statements of the sahabah and tabi'in are not reported. For that reason, the only means through which these can be explained is that of the Arabic language, and it is on the basis of language alone that they are elucidated. Besides that, should there be some difference in the tafsir of a certain verse, then, in that case too, the science of linguistics is used to run a test of veracity between varying opinions.
6. Deliberation and Deduction
The last source of tafsir consists of deliberation and deduction. The subtleties and mysteries of the noble Qur'an are an ocean with no shore, no end. Therefore, the more a person, who has been blessed with insight into the Islamic sciences by Allah Almighty, deliberates in it, the more he discovers ever-new mysteries and subtleties. As a result of this, commentators do present the outcomes of their respective deliberations as well, but mysteries and subtleties so described are found acceptable only when they do not go against the five sources mentioned above. So, should a person, while explaining the Qur'an, come out with a subtle point or independent judgment which is contrary to the Qur'an and Sunnah, Consensus (Ijm-a'), Language, or the statements of Companions and Successors, or stands in conflict with another principle of Shari'ah, that will then have no credence. Some mystics (RH) had started describing such mysteries and subtleties in tafsir, but investigative scholars of the ummah did not consider these trustworthy because the personal opinion of any person against the basic principles of the Qur'an, Sunnah and Shariah has obviously no weight. (al-ltqan, 2/184)
The rules relating to Israelite reports
Judaica or Isra'iliyya-t are narratives which have reached us through Jews and Christians. It may be noted that early commentators used to write down all sorts of narration's which reached them from an identified source. Many of these narration's were straight Judaica. Therefore, it is equally necessary to know what they really are. The reality is that some noble Companions and their Successors first belonged to the religion of the people of the Book, later on when they became Muslims and learnt the Qur'an, they came across several events relating to past communities in the Qur'an and which they had also read in the books of their previous religion. Therefore, while referring to the events mentioned in the Qur'an they would describe other details before Muslims which they had seen in the books of their old religion. These very details have entered into the books of tafsir under the name of 'Isra'iliyyat'. Hafiz ibn Kathir, who is one of the authentic research scholars, has written that there are three kinds of 'Isra-liyya-t':
1. Narration's the truth of which is proved from other evidences of 'the Qur'an and Sunnah, for instance, the drowning of Pharoah and the ascent of Sayyidna Musa (AS) onto Mount Tur (Sinai).
2. Narrations the falsity of which is proved from other evidences of the Qur'an and Sunnah, for instance, it appears in Judaic narration's that Sayyidna Sulayman (AS) had become (God forbid) an apostate in his later years. Its refutation is proved from the Qur'an. It is said there: 'It was not Sulayman who became an infidel, but the devils did become infidels' (2:102). To cite yet another example, it finds mention in Judaic narration's that (God forbid) Sayyidna Dawud (AS) (David) committed adultery with the wife of his general (Uriah), or, having him killed through all sorts of contrivances, ended up marrying his wife. This too is a blatant lie, and taking such narration's to be false is imperative.
3. Narration's regarding which the Qur'an, the Sunnah and the Shariah are silent, such as the injunctions of Torah etc., are subjects about which silence is to be observed as taught by the Holy Prophet neither confirm, nor falsify. There is, however, a difference of opinion among scholars whether or not reporting such narrations is permissible. Hafiz ibn Kathir has given the decisive word by saying that reporting these is permissible all right but doing so is useless because they cannot be taken as authentic. (Muqaddamah Tafsir ibn Kathir)