The interpreters’ first step in authoring works of interpretation was to collect the narrations that directly or indirectly dealt with the interpretation of the Quranic verses. These are the narrations from the Prophet (p.b.u.h.) or the Imams (a.s.) that are cited in interpreting the verses of the Quran. This method was often used to interpret the Holy Quran during the presence era and afterwards until the 4^th century (A.H.) when the Islamic world came upon a revolution in interpretation sciences and with the growth of rationalism, especially in the School of Baghdad, this achievement was expanded and crossed borders. Interpreters embarked upon ijtihad and, hence, they gained access to interpretational narrations in addition to other resources. Among these interpreters, Sheikh Tusi has extensively relied on narrations with a single transmitter in al-Tebyan fi Tafsir al-Quran although he has pointed out in the same work of interpretation that such narrations lack authority. These narrations often lack chain of transmission but they have been used in explaining the issues related to Quranic sciences, explaining the verses of the revealed prescripts, evaluating other narrations, endorsing or supporting the views of interpreters, and explaining theological issues. Sometimes, Sheikh Tusi has relied on documentational criticism and some other times on textual criticism but he has been mainly involved with textual criticism