Quran interpretation is one of the most important sciences and one of the best of it, since it deals with the word of Allah (God).
So, before an interpreter begins interpretation of the glorious Quran, it is compulsory on him to possess some factors that will qualify and guarantee his knowledge of the science of the Glorious Qur'an.
Among these factors are:
1 – He must know Arabic language very well,expecially Arabic grammar(nahw),Arabic morphology(sarf), Arabic eloquence(balagah) and all that Arabic language entails,because the Qur'an was revealed with the Arabic language and it is not possible for someone to understand it very well except with the understanding of the language.
2 – He must know the abbrogator (Nasikh) and the abrogated (Mansukh) of the Qur'an, so that he will not use the abrogated whose its rule has been raised, and leave behind the abrogator whose rule remains.
3 – He must have good knowledge of the prophet's traditions, because there are some verses that cannot not be understood except with the knowledge of His traditions.
4 – He should be conversant with the sayings of the companions of the prophet (may Allah be pleased with them all), because they witness the revelation of the Qur'an and they are the ones who know the interpretation of Allah's word most after the prophet (pbuh).
5 – He must know the knowledge of monotheism (Tawheed) very well, in order to bring out the rule that is in conformity with the good and authentic creed of Islam.
6- He must know the rules of Arabic language.
These are some of the factors affecting the personality of an interpreter of the Qu'an that the scholars of Islam have been written down in their books.