The old translations of the Quran are a precious legacy of the language of our ancestors and a treasure of authentic Persian words. In this article, which was obtained from broader research to revive and correct an ancient translation of the Holy Quran (1766 manuscript of Astan Quds Razavi library), we have investigated the unknown and rarely used words in this translation. A number of these words, such as the word "Rouijeh" equivalent to the Quranic word "Re’a" are completely unknown and are used only in this version and at most in another old translation of the Qur'an, and a larger number of them such as the words "Farwishkârân" equivalent to "Al-Ghafilin" " and "Varwareh" are equivalent to "Al-Ghorfat" and are rarely used and abandoned. Since the meaning of the words becomes clearer as they are used in the text, in addition to the Quranic and Persian equivalents of the old words, we have given the cases of their use in the target version and other translations of the Quran and sometimes in literary texts, and in some cases to clarify their meanings to We have also mentioned the words related to them. From examining these words and some other linguistic features of this version, we have come to the conclusion that due to the similarities with the Holy Qur'an, the language of this translation is closer to the type of the language of the Eastern region, especially the Sistan region.