Dunash ibn Tamim (Hebrew: דונש אבן תמים) was a Jewish tenth century scholar, and a pioneer of scientific study among Arabic-speaking Jews. His Arabic name was أبو سهل Abu Sahl; his surname, according to an isolated statement of Moses ibn Ezra, was "Al-Shafalgi," perhaps after his (unknown) birthplace. Another name referring to him is Adonim.
His first name seems to have been native to northern Africa, it was common among medieval Berbers. The younger contemporary of Ibn Tamim, Dunash ben Labrat, for instance, was born in Fez.
Details concerning Ibn Tamim's life and activities have been gathered principally from his Sefer Yetzirah commentary.
In this commentary, which was written in 955–956 CE, Saadia Gaon is mentioned as no longer living. The author refers, however, to the correspondence which was carried on when he was about twenty years of age between his teacher, Isaac Israeli ben Solomon, and Saadia, before the latter's arrival in Babylonia, consequently before 928; hence Tamim was born about the beginning of the tenth century.
Like his teacher, he was physician in ordinary at the court of the Fatimid caliphs of Kairouan, and to one of these, Isma'il ibn al-Ḳa'im al-Manṣur, Tamim dedicated an astronomical work, in the second part of which he disclosed the weak points in the principles of astrology.
Another of his astronomical works, prepared for Hasdai ben Isaac ibn Shaprut, the Jewish statesman of Cordova, consisted of three parts: (1) the nature of the spheres; (2) astronomical calculations; (3) the courses of the stars. The Arabian author Ibn Baitar, in his book on simple medicaments, quotes the following interesting remark on the rose, made by Ibn Tamim in one of his medicinal works: "There are yellow roses, and in Iraq, as I am informed, also black ones. The finest rose is the Persian, which is said never to open."
The Arabic original of Ibn Tamim's commentary on the Sefer Yetzirah no longer exists. In the Hebrew translations the manuscripts are widely dissimilar, and contain varying statements regarding the author. In several of these manuscripts Ibn Tamim is expressly referred to as the author; in one instance he is named again, but with his teacher, while in another Jacob ben Nissim is named, who lived in Kairouan at the end of the Tenth century.