another chapter the language of the Koran and the Ḥadíth was rapidly becoming obsolete as a spoken idiom outside of the Arabian peninsula: the 'perspicuous Arabic' on which Muḥammad prided himself had ceased to be fully intelligible to the Moslems settled in ‘Iráq and Khurásán, in Syria, and in Egypt. It was essential that the Sacred Text should be explained, and this necessity gave birth to the sciences of Grammar and Lexicography. The Philologists, or, as they have been aptly designated, the Humanists of Baṣra and Kúfa, where these studies were prosecuted with peculiar zeal, naturally found their best material in the Pre-islamic poems--a well of Arabic undefiled. At first the ancient poetry merely formed a basis for philological research, but in process of time a literary enthusiasm was awakened. The surviving _Ráwís_ were eagerly sought out and induced to yield up their stores, the compositions of famous poets were collected, arranged, and committed to writing, and as the demand increased, so did the supply.[260] [Sidenote: Corrupt tradition of the old poetry.] [Sidenote: Ḥammád al-Ráwiya.] [Sidenote: Khalaf al-Aḥmar.] In these circumstances a certain amount of error was inevitable. Apart from unconscious failings of memory, there can be no doubt that in many cases the _Ráwís_ acted with intent to deceive. The temptation to father their own verses, or centos which they pieced together from sources known only to themselves, upon some poet of antiquity was all the stronger because they ran little risk of detection. In knowledge of poetry and in poetical talent they were generally far more than a match for the philologists, who seldom possessed any critical ability, but readily took whatever came to hand. The stories which are told of Ḥammád al-Ráwiya, clearly show how unscrupulous he was in his methods, though we have reason to suppose that he was not a typical example of his class. His contemporary, Mufaḍḍal al-Ḑabbí, is reported to have said that the corruption which poetry suffered through Ḥammád could never be repaired, "for," he added, "Ḥammád is a man skilled in the language and poesy of the Arabs and in the styles and ideas of the poets, and he is always making verses in imitation of some one and introducing them into genuine compositions by the same author, so that the copy passes everywhere for part of the original, and cannot be distinguished from it except by critical scholars--and where are such to be found?"[261] This art of forgery was brought to perfection by Khalaf al-Aḥmar († about 800 A.D.), who learned it in the school of Ḥammád. If he really composed the famous _Lámiyya_ ascribed to Shanfará, his own poetical endowments must have been of the highest order. In his old age he repented and confessed that he was the author of several poems which the scholars of Baṣra and Kúfa had accepted as genuine, but they laughed him to scorn, saying, "What you said then seems to us more trustworthy than your present assertion."