Hasun ben Mashiach

10th century Karaite scholar
Hasun ben Mashiach was a Karaite scholar who flourished in Egypt (or Babylonia) in the first half of the tenth century. According to Steinschneider, "Hasun" is a corrupted form of the Arabic name "Hussain," the ו being easily confounded in manuscript with the י Hasun, or, as he is generally quoted by the Karaite authorities, ben Mashiah, was a younger contemporary of Saadia Gaon, whom, according to Sahl ben Matzliah in his Tokahat Megullah, he once challenged to a religious controversy. Hasun was the author of a polemical work, written probably in Arabic, in which he refuted one of Saadia's unpublished anti Karaite writings, which came into his possession after the death of the author. Owing to a misunderstanding of a passage (§ 258) in the Eshkol ha Kofer of Hadassi, Ḥasun was erroneously credited with the authorship of the anonymous chapter on theodicy, entitled Sha'ar Tzedek (St. Petersburg, Firkovich MSS. Nos. 683, 685), in the religio philosophical work "Zikron ha Datot," and of Quppat ha Rokelim. Simḥah Isaac Luzki attributes to Ḥasun also a work on the precepts (Sefer ha Mitzvot). Abraham ibn Ezra, in his introduction to the commentary on the Pentateuch, quotes a Karaite scholar named Ben Mashiah, who is probably identical with Hasun.

Singer, Isidore and Isaac Broydé. "Mashiach, Hasun ben". Jewish Encyclopedia. Funk and Wagnalls, 1901 1906, which cites the following bibliography:
Pinsker, Liḳḳuṭe Ḳadmoniyyot, p. 114;
Fürst, Gesch. des Karäert. ii. 46;
Gottlober, Biḳḳoret le Toledot ha Ḳera'im, p. 168;
Steinschneider, Hebr. Bibl. iv. 48;
idem, Cat. Bodl. p. 2169;
idem, Cat. Leyden, p. 390;
idem, Hebr. Uebers. p. 460;
idem, Die Arabische Literatur der Juden, § 41. S. I. Br