The "Musar Haskel"
Of Hai's poetical writings few have been preserved, and even of these the genuineness is doubted. The didactic poem "Musar Haskel" is generally regarded as authentic, though Dukes expressed some doubts as to its genuineness, as old Jewish authors like al-Harizi and ibn Tibbon do not mention it; and Steinschneider also regarded it as of doubtful authenticity. The first edition appeared about 1505 (see Fano); others were published in Constantinople (1531), in Paris (1559), and elsewhere. The modern editions are as follows: Dukes, Ehrensäulen, p. 96; Grätz, Blumenlese, p. 27; Steinschneider, Musar Haskel, Berlin, 1860; Weiss, Liqquṭe Qadmonim, Warsaw, 1893; Philipp, Sämmtliche Gedichte des R. Hai Gaon, Lemberg, 1881; a Latin translation by Jean Mercier, Cantica Eruditionis Intellectus Auctore per Celebri R. Hai, Paris, 1561; another by Caspar Seidel, Carmen Morale ΣτροφορυΘμον Elegantissimum R. Chai, etc., Leiptzig, 1638. The "Musar Haskel" consists of 189 double verses in the Arabic meter "rajaz," and it is said to have therefore received the title of "Arjuzah." If it really belongs to Hai, he was, as far as is known, the first Eastern writer to use an Arabic meter in Hebrew poetry. Every strophe is complete in itself, and independent of the preceding strophe.
Some piyyutim are ascribed to him, as the piyyut beginning with the words "Shema' qoli," preserved in the Sephardic liturgy for the evening of Yom Kippur.
Many spurious writings have been ascribed to Hai, especially by later kabalists. Among them are a Sefer kol ha-Shem ba-Koah; Pitron Halomot, Ferrara, 1552; Sefer Refafot, ib.; Perush me-'Alenu; Teshubah, on the thirteen rules of R. Ishmael and on the Ten Sefirot; A Letter to the Priests of Africa. Some of the responsa attributed to him are mere forgeries. Others again were falsified or mutilated by later additions and interpolations, as, for instance, the one containing attacks upon Aristotle and his philosophy
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