The narrations of the reason for the revelation form a significant part of the commentary narrations and different commentators have interacted with them in different ways according to their methods, tendencies and assumptions. This research, using analytical-descriptive method and referring to library sources, aims to answer this basic question: "What is the validity and function of narrations that causes the decline in the view of the commentators of Tafsir Al-Manar and Al-Mizan?" Identifying the viewpoints of these two commentators helps the researchers of Qur'anic sciences and interpretation to identify the way in which the commentators of these two commentaries interact and deal with the narrations of the revelation, which clarifies the necessity of investigating the viewpoints of the commentators of these two commentaries about the narrations of the revelation.Because the examination of this issue in these two commentaries can represent the consistent approach of the contemporary commentators of the Islamic world in dealing with the narrations that cause descent, which in turn will cause approximation and convergence among the commentators. According to Rashid Reza, the narratives of the causes of descent are not very valid. Allameh Tabataba'i also considers many narrations of the causes of descent to be non-musnad and weak. According to Rashid Reza, the narrations of the reasons for the revelation do not only clarify the meaning of the verse, but also sometimes cause the true meaning of the verse to remain hidden, despite Allameh Tabatabai's view on the method of interpreting the Qur'an to the Qur'an and trying to free the text of the Qur'an from others. External components such as the means of descent, in some cases we witness that he has used the narrations of the causes of descent in different places in Al-Mizan's Tafsir.