Isaac ben Samuel of Acre

Isaac ben Samuel of Acre (fl. 13th-14th century) (Hebrew: יצחק בן שמואל דמן עכו, "Yitzhak ben Shmuel d'min Akko") was a kabbalist who lived in the Land of Israel.

According to Azulai ("Shem ha-Gedolim") he was a pupil of Nahmanides. He was at Acre when that town was taken by Al-Malik al-Ashraf, and was thrown into prison with many of his coreligionists; but he escaped the massacre, and in 1305 went to Spain. Abraham Zacuto states, in his "Yuḥasin," that Moses de Leon discovered the Zohar in the time of Isaac of Acre. But Isaac doubted the authenticity of the Zohar, not having heard of it in the Holy Land, and made inquiries about it of Naḥmanides' pupils, without, however, any satisfactory result. When he met Moses of Leon at Valladolid, the latter took an oath that he had in his house at Avila a copy of the Zohar, written by Shimon bar Yochai himself. But Moses of Leon died before he could return to Avila, and Isaac, more than ever desirous of obtaining the truth, consulted at Avila a certain David Rafan. The last-named told Isaac that Moses of Leon's wife and daughter had revealed to the wife of a certain R. Joseph the fact that Moses of Leon had written the book himself. Grätz ("Gesch." vii. 211) takes this story as historical, but Landauer (in "Orient, Lit." vi. 710-713) shows it to be apocryphal, and demonstrates that the Zohar was discovered much later.

Isaac of Acre is frequently quoted by Elijah de Vidas in his "Reshit Ḥokmah," and by R. Hayyim Vital in his "Megillat Setarim." He was an expert in composing the sacred names ("ẓerufim"), by the power of which angels were forced to reveal to him the great mysteries (Azulai, l.c.). According to Azulai he wrote many kabbalistic works. Those that are known are: "Meirat Enayim," a kabbalistic commentary on Naḥmanides' commentary to the Pentateuch; "Sefer ha-Sodot," mentioned in the "Nobelot Ḥokmah" of Joseph Solomon Delmedigo; "Ketem Paz," a kabbalistic work mentioned by Moses Botarel in his commentary to the Sefer Yezirah, and the author of which he calls "Isaac ben Samuel," identified by Michael ("Or ha-Ḥayyim," No. 1088) with Isaac ben Samuel of Acre; "Liḳḳuṭe Shoshanim," possibly a compendium of the "Sefer ha-Sodot." It appears from the "Reshit Ḥokmah" that Isaac of Acre wrote also a book on ethics. A specimen of the "Me'irat 'Enayim" was published by Adolf Jellinek in his "Beiträge"; the remainder of Isaac's works are still in manuscript.

One of Isaac of Acre's most interesting and timely findings has to do with the age of the Universe. Isaac states that, contrary to what the creation myth of Genesis says (that the world was created in 6 days), the universe is actually 15,340,500,000 years old. Isaac arrived at this conclusion by distinguishing between eartly "solar years" and "divine years," based on a verse from Psalms, which states that "A thousand years in Your sight are but as yesterday" (Psalm 90:4). If each day of a divine year is equal to a thousand earthly "solar years," then a divine year would be 365,250 years long. Isaac then makes some other calculations based on the Talmud and the Biblical sabbatical year, and arrives at the number 15.3405 billion, which is astoundingly close to the scientific estimation, which places the occurrence of the Big Bang at 13.7 ± 0.2 billion years ago.

Jewish Encyclopedia bibliography

*Grätz, Gesch. 3d ed., vii. 186, 211, 427-428;
*Abraham Zacuto, Yuḥasin, ed. Filipowski, pp. 95, 96, London, 1857;
*Azulai, Shem ha-Gedolim, p. 54;
*Jellinek, Beiträge, ii., xiii.;
*Steinschneider, Cat. Bodl. col. 2523;
*M. H. Landauer, in "Litteraturblatt des Orients", vi. 182, 224, 509
*Michael, Or ha-Ḥayyim, p. 513, No. 1088.