The books of tafseer have been divided into two general categories according to the emphasis of their authors in their explanations. The tafseers of those who restricted their expla-nations to transmitting what was explained in the Qur’aan or stated by the Prophet (r), his companions, and their students were referred to as tafseer bir-riwaayah or tafseer bil-ma’thoor (tafseer according to transmission). The authors of such tafseers also avoided unfounded interpretations and unnecessary expla-nations and always accepted authentic narrations. This is not to say that such tafseers are totally free of personal judgment and opinion, for any tafseer, of necessity, must reflect the opinion of the individual who compiles it. But in this case, personal opinion was kept to a minimum.

On the other hand, those tafseers in which the authors often relied on their personal opinions for explanations, inter-pretations and deductions were called tafseer bid-diraayah or tafseer bir-ra’y (tafseer according to opinion). In some of these types of tafseers, narrated explanations from the Prophet (r), the sahaabah,and their students (taabi‘oon) are mentioned prior to personal interpretation, and the deductions or opinions are in agreement with narrated explanations, grammatical rules, and lexical meanings, while in others there is a partial or even total disregard for narrated explanations, grammatical rules, and word meanings. Tafseers of the first type are acceptable, while those based mostly or solely on unfounded opinion are considered heretical or bordering on heresy.

Allaah and His Prophet (r) have expressly forbidden unfounded explanations of the Qur’aan. For example, it was forbidden in the verse,

The Prophet (r) also condemned expression of uninformed opinion in religious matters, saying,

“Allaah won’t remove knowledge after giving it to you by removing it (from you). Rather he will remove it from (later generations) by taking (the souls of) the scholars along with their knowledge, until only ignorant people remain. They will be asked for religious verdicts, so they will issue verdicts based on their opinions, leading others astray and going astray themselves.”112

Therefore, it could be generally said that narrations from the Prophet (r), the sahaabah, and the taabi‘oon are superior to those based on opinion. But if the narrations are not authentic, such tafseers may then be actually worse than some of those based on opinion.

A brief description of some of the most famous tafseers and their authors follows.