Judah ben Elijah Hadassi (in Hebrew, Yehuda ben Eliyahu) was a Karaite Jewish scholar, controversialist, and liturgist who flourished at Constantinople in the middle of the twelfth century. He was known by the nickname "ha-Abel," which signifies "mourner of Zion." Neubauer thinks that "Hadassi" means "native of Edessa" Nothing of Hadassi's life is known except that he was the pupil of his elder brother Nathan Hadassi. He dealt with Hebrew grammar, Masorah, theology, and philosophy, and knew Arabic and Greek well. Eshkol ha-Kofer Hadassi acquired his reputation by his treatise Eshkol ha-Kofer or Sefer ha-Peles, on which he began work on 9 October 1148. It is a treatise on the Ten Commandments, in which the author endeavored to explain them philosophically, and in which he applied all his analytical talent and scholarship. He starts from the premise that all laws contained in the Pentateuch, and those added by the Rabbis, as well as the minor ethical laws by which the Jews regulate their daily life, are implied in the Ten Commandments. Hadassi enumerates, under the head of each of the Ten Commandments, a complete series of coordinate laws; and the whole work is mapped out according to this plan. The work embodies not only much of the science of his time, but even legends and folk-lore, so that it has appropriately been termed "a sea of learning." It is written in rhymed prose, the general rhyme throughout the work being ך; and the initial letters of the successive verses form alternately the acrostics of אבגד and תשרק, repeated 379 times. The alphabetic chapters 105-124 are, however, in the regular form of poems. The first commandment (alphabets 1-95) affirms the existence of God and covers the duties of the created toward the Creator, dealing, for instance, with prayer, repentance, future punishment and reward, and resurrection. Beginning with alphabet 35, Hadassi considers the nature of God, of creation, of angels, of the celestial bodies, etc. In fact, this part of the work is a compendium of religious philosophy, astronomy, physics, natural history, geography, and folk-lore. The second commandment (alphabets 96-129) affirms the unity of God. Here Hadassi refutes the views of other sects; for example, the Christians, Rabbinites, Samaritans, and Sadducees, who maintain the eternity of the world. He is indignant at those who identify the Karaites with the Sadducees, and shows great animosity toward the Rabbinites. Alphabets 99-100 contain a violent