Muʿtazilite ideas and tendencies probably began to percolate into Jewish culture by the early ninth century. The reception of Muʿtazilite Kalām among Jews can be observed not only among those who wrote theological works, but also among those who were not professional theologians, both Rabbanites and Karaites. The presence of Kalām doctrines seems to have been rather widespread and longlasting, found among some Karaites until at least the seventeenth century.
Nemoy“Pseudo-Qumisian Sermon” p. 55(with some alterations). Al-Qūmisī’s objections to foreign books is also expressed in his commentary to Hosea and Micah. (See Markon Pitron Shneim ʿAsar p. 4 and n. 23 for a number of other similar expressions). Ben-Shammai suggests that “one should assume several decades for the process of absorbing Muʿtazilite theology into Karaite thought before presenting it as genuinely Jewish in contradistinction to other “foreign” ideologies” thus coinciding “with the period of al-Muqammaṣ’s activity.” (Ben-Shammai “Major Trends” pp. 341f.). I think that this process of “domestication” took much longer.—There is also a manuscript fragment containing the beginning of a Judeo-Arabic work on divine unity (כתאב תפסיר אלתוחיד במעקול) attributed to Daniel ben Moshe (al-Qūmisī) published by Zucker ʿAl Targum Rasag pp. 176–182 481–485. The attribution to al-Qūmisī is still not certain and there may have been confusion between Daniel b. Moshe al-Qūmisī and Dāwūd al-Qūmisī a tenth-century Jewish mutakallim mentioned by al-Masʿūdī (al-Tanbīh pp. 112–114). On Dāwūd al-Qūmisī see also Sklare Samuel ben Ḥofni Gaon p. 117 n. 59.