The verse “We have neglected nothing in the Book (of Our decrees)” is one of the controversial cases among the commentators and theologians that one of the factors of this controversy refers to semantics of the word “Book”. Commentators have interpreted this word by different meanings among which, in most of the commentaries, the word “Book” has been interpreted as the Quran and the divine memory so that a number of the commentators have committed errors in interpretation of the majority of the opinions. Accordingly, some people believe that for most of the commentators, “Book” is the Quran and some others believe that “Book” refers to the divine memory. According to the effect of each one of these viewpoints on understanding and interpretation of the above-mentioned verse, various commentaries with different commentary inclinations have been investigated in this paper and along with explaining the different meanings of “Book”, different opinions of the commentators are analyzed in this regard and finally, based on the opinions of the majority of commentators and rational and textual evidences, the best viewpoint about commentary of verse 38 of Al-An’am is analyzed.