Isaac ben Samuel of Acre
View of the Zohar
Isaac ben Samuel was at the Crusader-controlled town of Acre when town was taken by a Mamluk army led by Al-Ashraf Khalil. He was arrested and thrown into prison with many other Jews, but 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.
However, 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 Isaac met Moses of Leon at Valladolid, the latter took an oath that he had a copy of the Zohar written by Shimon bar Yochai himself in his house at Ávila. However, de Leon died before he could return to Ávila, and Isaac, more than ever desirous of obtaining the truth, consulted at Ávila a man named David Rafan.
Rafan 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. Historian Heinrich Graetz takes this story as historical, but Landauer shows it to be apocryphal and demonstrates that the Zohar was discovered much later.
Quotations and works in Kabbalah
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.
Theory of age of the Universe
Isaac states that the universe is actually 15,340,500,000 years old. Isaac arrived at this conclusion by distinguishing between earthly "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 said number. The scientific estimation places the occurrence of the Big Bang at 13.798 ± 0.037 billion years ago.
- The book of direction to the duties of the heart - Page 69. "Isaac of Acre was a Palestinian kabbalist of the thirteenth century who fled to Spain after the city of Acre was taken."
- In Shem ha-Gedolim
- Gesch. vii. 211
- In Orient, Lit. vi. 710-713
- Kaplan, Aryeh (January 1993). Immortality, resurrection, and the age of the universe: a kabbalistic view. Ktav Publishing House. p. 9. ISBN 978-0-88125-345-0.
- Planck collaboration (2013). "Planck 2013 results. XVI. Cosmological parameters". Submitted to Astronomy & Astrophysics. arXiv:1303.5076.
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.