[6] In this capacity, his philosophical work The Book of Beliefs and Opinions represents the first systematic attempt to integrate Jewish theology with components of ancient Greek philosophy.He immigrated to ancient Israel (in the Abbasid province of Bilad Al-Sham) in 915 at the age of 23, where he studied in Tiberias under the scholar Abu Kathir Yaḥya al-Katib (known as Eli ben Yehudah ha-Nazir in Hebrew), a Jewish mutakallim or theologian also mentioned by ibn Ḥazm.Saadia, in Sefer ha-Galui, stresses his Jewish lineage, claiming to belong to the noble family of Shelah, son of Judah,[7] and counting among his ancestors Hanina ben Dosa, the famous ascetic of the first century.[9] Later, one of Saadia's chief disputants was the Karaite by the name of Abu al-Surri ben Zuṭa, who is referred to by Abraham ibn Ezra, in his commentary on Exodus 21:24 and Leviticus 23:15).Rabbi Aaron ben Meïr, head of the Palestinian Gaonate (then located in Ramla), claimed a tradition according to which the cutoff point was 642/1080 of an hour (approximately 35 minutes) after noon.[clarification needed] In that particular year, this change would result in a two-day schism with the major Jewish communities in Babylonia: according to Ben Meir the first day of Passover would be on a Sunday, while according to the generally accepted rule it would be on Tuesday.Saadia addressed a warning to him, and in Mesopotamia, he placed his knowledge and pen at the disposal of the exilarch David ben Zakkai and the scholars of the academies, adding his letters to those sent by them to the communities of the Jewish diaspora (922).In Babylonia, he wrote his Sefer haMo'adim, or "Book of Festivals," in which he refuted the assertions of Ben Meïr regarding the calendar and helped to avert from the Jewish community the perils of schism.[16] The Yemenite Jewish community also adopted thirteen penitential verse written by Saadia for Yom Kippur, as well as the liturgical poems composed by him for Hoshana Rabbah, the seventh day of Sukkot.[17] As much as Saadia's Judeo-Arabic translation of the Torah (Tafsīr) has brought relief and succour to Jews living in Arabic-speaking countries, his identification of places, fauna and flora, and the stones of the priestly breastplate, has found him at variance with some scholars.[19] Saadia's method of conveying names for the fowls based on what he had received by way of an oral tradition prompted him to add in his defense: "Every detail about them, had one of them merely come unto us [for identification], we would not have been able to identify it for certain, much less recognize their related kinds.[33] In some instances, Saadia's biblical translations reflect his own rationale of difficult Hebrew words based on their lexical root, and he will, at times, reject the earlier Targum for his own understanding.[37] The sheraqraq (Arabic: شقراق, romanized: šiqirrāq) is a bird that harbingers rain in the Levant (around October), for which reason the Talmud says: "When raḥam arrives, mercy (raḥamīm) comes into the world.The position assigned to Saadia in the oldest list of Hebrew grammarians, which is contained in the introduction to Abraham ibn Ezra's "Moznayim," has not been challenged even by the latest historical investigations.In his commentary on the Sefer Yetzirah, Saadia sought to render lucid and intelligible the content of this esoteric work by the light of philosophy and scientific knowledge, especially by a system of Hebrew phonology which he himself had founded.Nonetheless, he clearly considered the work worthy of deep study and echoes of Sefer Yetzirah's cosmogony do appear in "Kitab al-Amanat wal-I'tiḳadat" when Saadia discusses his theory of prophecy.