Mutazili discussions of the abrogation of the Torah Ibn Hallad (4th/10th century) and his commentators

Abu Ali Muhammad b. Hallad al-Basr i, a distinguished disciple of Abu Hasim al-G?ubbai (d. 321/933), wrote a Kitab al-Usu l together with an autocommentary, both of which are lost. Substantial portions of his Kitab al-Usu l, though, have reached us embedded in two works by later Mutazili authors, viz. the Kitab Ziyadat Šarh al-usu l by the Zaydi Imam al-Nati q bi-l-Haqq Abu Talib Yahy? a b. al-Husayn b. Harun al-ButHani (d. 424/1033) and a second supercommentary or taliq that was apparently composed by the Zaydi author Ali b. al-H?usayn b. Muh?ammad al-Daylami Siyah [Šah] Sarigan [Sarbigan]. Both works provide valuable and supplementary information on Ibn Hallad's original Kitab al-Usu Šarh al-usu l. By way of example, the section on the abrogation of the Torah from the two commentaries is offered in a critical edition, and the similarities and discrepancies between the two works are discussed in detail on the basis of this section. The issue discussed here is one of the main arguments in polemics between Muslims and Jews.