The methodology of Comparative study of Quoranic commentaries

In Quranic studies vanetres of methods have been employed, particularly in the recent century it has been done with the latest procedures. This study deals with one of these methods i.e. the comparative one. This kind of study varies according to the two field of knowledge compared:an issue in Quran and the Testaments, a controversial subject in Shiite and Sunnite exegesis, a piece of data in natural science or humanities with that of Quran.This article has examined the procedure followed in such studies, indicating its fundamentals and deficiencies, along with examples for each cases.