The book: The vocabulary of the words of the Quran by Abi al-Qasim al-Husayn ibn Muhammad ibn al-Fadl, known as the deceased Isfahani, who died in the first quarter of the fifth century AH is one the best of language books and the Qurans translations, in which his compiler made a good effort in singularities in the study of strange vocabulary in the download, an exhaustive comprehensive study that dealt with often Its indications and the evolution of those indications and their variation according to the subject, custom, truth, metaphor, language or law, etc., which is a disturbance of what distinguished this book from the rest of the books of the Quran, such as Ibn Qutayba (d. 276 AH) and Abu Bakr Muhammad al-Sijistani (d. 330 AH), and others became a reference for scholars in different ages.