R. Eliezer ben Samuel ben Moses de Avila (known as Rav Adda, 1714–1761) was born in Salé, Morocco and served as rabbi in Rabat. His commentaries on the Talmud, written while he was still a youth, are noteworthy for their acumen and independence. R. Avila was a scion of an illustrious family of scholars. His father R. Samuel, his grandfather R. Moses, and R. Ḥayyim ben Moses ibn Attar, his maternal uncle, were all prominent Talmudists and well-known authors. Like his uncle R. Hayyim, R. Avila desired to see the Holy Land and intended to settle in Jerusalem; but, owing to an epidemic and a famine in Morocco, which lasted a long time and compelled him to leave Rabat for a while, he lacked the necessary means to do so. R. Avila was a prolific writer, and among his manuscripts were found notes dating from his sixteenth year. After his death the following of his works, in addition to Be'er Mayim Hayyim, appeared: (1) Magen Gibborim (Leghorn, 1781-85), in two volumes; the first containing novellæ to the treatises, Baba Mezi’a and Horayot; the second, novellæ to the treatises Ketubot and Ḳiddushin; (2) Milhemet Mitzah (ib., 1806), containing the principles of the Talmudic and post-Talmudic Halakah. Some funeral sermons are appended under the title Hesed ve-Emet; (3) Ma'yan Gannim, explanations and elucidations of R. Jacob ben Yeḥiel's "Turim," especially of the second and third parts (ib., 1806).

As these works show, R. Avila confined his work in rabbinical literature to the Halakah. In this province at all events he was an undisputed master; and his epithet, "Ner ha-Ma'arabi" (Light of the West) was not undeserved. His greatness as a Talmudist was recognized even by the most eminent Palestinian scholars, who, in the capacity of "Meshullaḥim," had the opportunity of becoming personally acquainted with him. It was to them that he owed this title. Among the scholars of Morocco, Avila, with his avowed inclination toward the casuistic treatment of the Halakah (Pilpul), was a rare personality. This tendency explains his independent attitude toward his colleagues, on whom his keen and brilliant intellect made a deep impression, as shown in his responsa. These responsa contain many interesting items concerning the condition of the Jews in Morocco. R. de Avila left one child, a daughter, who married her cousin Solomon de Avila, a man of wealth and a distinguished Talmudist. The sons by this marriage, Moses and Samuel, were, in a way, the successors of their grandfather, both being rabbis and Talmudic teachers in Rabat. Joseph de Avila, son of Moses, was the publisher of the works of his great-grandfather Eliezer. He died in Rabat. To this day the Jews of Morocco go on pilgrimage to his grave.

דף [4,ב-5,ב]: הקדמות ר' שלמה די אבילה, חתן המחבר, ור' יוסף ב"ר משה די אבילה. דף [2,א-4,א]: הסכמות דייני ליוורנו: ר' יעקב נוניס ואיס, ר' שם טוב בן סאמון ור' משה אהרן רחמים פייצה, תקס"ו; רבני מכנאסא: ר' יעקב טולידאנו ור' מרדכי בירדוגו, סיון תקכ"ז; ר' חיים טולידאנו, סאלי, ראש חודש אלול תקכ"ג; רבני טיטואן: ר' יעקב ן' מלכא, ר' אפרים מונסנייגו, ר' יהודה אבודרהם ור' יהודה קורייאט, מרחשון תקכ"ה [שלוש ההסכמות האחרונות הועתקו מ"מגן גבורים", ליוורנו תקמ"א].