Imām Muḥammad b. Abi Bakr al-Rāzī (d. 666 AH) compiled his Arabic dictionary Mukhtār al-Ṣiḥāḥ as an abridgement of Al-Ṣiḥāḥ by Al-Jawharī (d. 393 AH).
Al-Jawharī was one of the last of the classical lexicographers who spent time with Bedouin Arabs, checking the accuracy of what he had studied of the Arabic language in Iraq. In his dictionary, Al-Ṣiḥāḥ, he endeavoured to include only that which was authentically classical Arabic, and in this he was, by general consensus, to a great extent successful. It was for this reason that his dictionary came to be regarded so highly.
Al-Rāzī’s Mukhtār al-Ṣiḥāḥ greatly condensed Al-Ṣiḥāḥ, by including only those words which were in fairly common usage, or were used in the Qur`ān. Al-Rāzī’s aim, as he states in his introduction, was to compile an Arabic dictionary which contained only those words which he believed it was essential for a serious scholar to know and memorize.
The quality of Al-Ṣiḥāḥ and the usefulness of having an abridgement which could easily be memorized has lead to Mukhtār Al-Ṣiḥāḥ becoming very widely known and used. Its usefulness, however, for a student who does not wish to memorize it, is limited, not least because Al-Rāzī omits so much that he assumes the Arabic student will know.
For example, he states in his introduction that the usual verbal noun of an intransitive verb on the morphological scale of (fa’ala yaf’ilu) is fu’ūl, and so it is not necessary to give the verbal noun of such verbs; one can assume that they follow the usual pattern.
However, in the dictionary one finds that Al-Rāzī sometimes includes such verbal nouns (e.g. julūs), and sometime omits them (e.g he doesn’t have ṣudūf), which, whilst it won’t confuse someone comfortable with Arabic morphology, will certainly trouble the beginner.