Rabbi Abraham Ben David Posquieres (known as Rabad, c. 1125–1198); was born in Narbonne, and died in PosquiIres, a small city near Nimes famous for the yeshivah he established there. He lived during a remarkable period of efflorescence of intellectual activity in southern France. A man of many literary achievements, his penetrating criticism of Maimonides' Mishneh Torah established him as an authoritative rabbinic scholar and earned for him the epithet of ba'al hassagot (“the critic” or “animadversionist” par excellence). His father-in-law, R. Abraham b. Isaac, who headed the rabbinical court in Narbonne, exerted considerable influence on Rabad, whose brilliance he fully appreciated. Rabad studied with R. Moses b. Joseph and R. Meshullam b. Jacob of Lunel, two of the most respected and influential scholars of the time. It also seems safe to assume that the enlightened atmosphere of his circle widened the scope of Rabad's learning so that he developed into a keen and resourceful halakhist, undisputed master in his own field, and highly knowledgeable in developments in related areas (philosophy and philology).

A mature scholar, prominent in Montpellier and Nimes, and a man of great wealth (it has been suggested that he dealt in textiles), he settled permanently in Posquieres, except for a short period (1172–73) when he fled to Narbonne and Carcassonne as a result of hostility on the part of the local feudal lord. He founded and directed a school to which advanced students from all parts of Europe flocked and he provided for all the needs of indigent students out of his own pocket. Some of his students and close followers, R. Abraham b. Nathan ha-Yarhi, R. Isaac ha-Kohen, R. Meir b. Isaac, R. Jonathan b. David ha-Kohen of Lunel, R. Asher b. Saul of Lunel, and his own son R. Isaac the Blind (of PosquiIres) became distinguished rabbis and authors in the principal Jewish communities of Provence, thus extending Rabad's influence and contributing to significant literary developments at the end of the 12th and the beginning of the 13th centuries. He himself asserted that his word was law in all Provence (Temim De'im (Lvov, 1812), 12a–b, no. 113). Scholars from Franco-Germany, Spain, North Africa, Italy, Palestine, and Slavic countries knew, studied, and respected him. Nahmanides describes his erudition and piety with great awe and R. Solomon b. Abraham Adret says that Rabad revealed unfathomed depths of the law “ as if from the mouth of Moses, and explained that which is difficult” (Torat ha-Bayit, Beit ha-Nashim, introduction). There is not a single commentator on Maimonides who is not by the same token a close, appreciative student of Abraham.

Rabad’s literary activity was original and many sided. His works may be classified under the headings of codes of rabbinic law, commentaries on various types of talmudic literature, responsa, homiletic discourses, and critical annotations and glosses (hassagot) on standard works of rabbinic literature. His writings are characterized by precision in textual study, persistence in tracing statements back to their original source, discovery of later interpolations, and logical analysis of problems. He was one of the most skillful practitioners of the critico-conceptual method of talmudic study - probing into the inner strata of talmudic logic, defining fundamental concepts, and formulating disparities as well as similarities among various passages in the light of conceptual analysis. As a result, abstract, complex concepts, which were discussed fragmentarily in numerous, unrelated sections of the Talmud, are for the first time defined with great vigor and precision. Many of his theories and insights were endorsed and transmitted by subsequent generations of talmudists and incorporated into standard works of Jewish law up to the Shulhan Arukh and its later commentaries.

בעל הנפש אשר חבר ... רבינו אברהם בר דוד ... על הלכות נדה, אשר לא נדפסו מזמן שנת שס"ב לפ"ק. ועתה הוספנו הגהות על ספר בעל הנפש, כפי שנדפסו לבד בווינציאה, בלי גוף הספר, בשנת תק"א ... כי שם נמצא כתוב יושר ספר בעל הנפש עצמו, מיושר ... כי אותן שנדפסו בשנת שס"ב היו מטושטשין מאוד שהיו חסירים כמה חתיכות וממש בכל שורה ושורה היו חסירים כמה תיבות, והצגנו על מקומם הראוים להן ... ע"י ... ר' אברהם נר"ו בן התורני ... מנחם מענקה דיינא רבא דק"ק הלברשטט ... והשגות מרבינו ... זרחיה הלוי זצ"ל, אשר עשה ואשר נלחם על ספר בעל הנפש. והלכות נדה להרמב"ן ז"ל. וחדושים הרב הגאון רבינו ניסם[!] על מסכת נדה ...

דף לג-לט,א: השגות הרז"ה על ספר בעל הנפש. דף לט,ב-מ,א: חרוזי הרז"ה ז"ל. דף מ,א-מה,ב: הלכות נדה לרבינו משה בר נחמן זצ"ל. דף מו,א-עד,א: חידושי הר"ן למסכת נדה. חידושי הר"ן על נדה, השגות הרז"ה על בעל הנפש, חרוזי הרז"ה, הלכות נדה להרמב"ן וההגהות על בעל הנפש ("בלי גוף הספר") נדפסו תחילה בספר "תודת שלמים", ויניציאה תק"א, חלק א, "זבחי תודה". הסכמה: ר' דוד ב"ר נפתלי הירש [פרענקל] אב"ד ברלין ועמו הדיינים ר' נפתלי הירץ ב"ר בנימין זאב, ר' יואל [זאקש] ב"ר יקותיאל מגלוגא ור' ירמיה ב"ר נפתלי הירש מהלברשטט, ג שבט תקכ"ב.