Ibn Migash enjoyed an outstanding reputation among his contemporaries. Maimon, the father of Moses Maimonides, was apparently among his many pupils, and Maimonides, especially in his novellae on the Talmud, frequently relies upon the traditions of Ibn Migash, which, as he states, he had received from his father. In his introduction to his commentary on the Mishnah, he says of him, "The understanding of that man in Talmud was awe-inspiring... so that it could almost be said of him that never before had there been his like." Maimonides' attachment to Ibn Migash is so strong that for a long time he was erroneously thought to have been his pupil. Judah Halevi, from youth the friend of Ibn Migash, composed poems of praise in his honor, and it was he who formulated the letter to the scholars of Provence in which Ibn Migash sought an acquaintance with them and their teachings. This letter is the earliest extant document on the ties between the centers of learning in Provence and Spain.

Very little of Ibn Migash's work is extant. His novellae to Bava Batra (Amsterdam, 1702) and Shevu'ot (Salonika, 1759) have been published, but his commentary must have embraced at least half of the Talmud, and even the portion published is not complete in itself. His novellae to Bava Batra are quoted more extensively and fully in the works of other rishonim, and are found in superior form in the Shitah Mekubbezet to that tractate, and in Aghmati's work, Sefer ha-Ner. A relatively small number of his responsa (translated from the original Arabic) have been published (Salonika, 1786); some are included in the works of others (e.g., in the responsa Pe'er ha-Dor, Amsterdam, 1765), and more are extant in manuscript. He is known to have composed a book of comments (which is not, however, extant) on the Hilkhot ha-Rif of his teacher. The works of Ibn Migash decisively influenced the study of Talmud in Spain and Provence. Meir Abulafia, who summed up the teaching of the Spanish scholars until the generation of Nahmanides incorporates - mostly anonymously - many of Ibn Migash's comments in his work. So does Nahmanides, who transmitted them to his pupils and followers, such as Solomon b. Abraham Adret and Yom Tov b. Abraham Ishbili (the Ritba). They were well known in Provence, too, already being quoted by Abraham b. Isaac, who frequently relies upon them in his responsa.

Appended are six responsa of the Hatam Sofer, R. Moses Sofer, and assorted novellae.

חידושי ר"י מיגאש וחידושי מהרש"י נדפסו תחילה בתוך ספר אוריין תליתאי, שהוציא ר' יוסף מודיליאנו, שאלוניקי תקי"ח; שם [תקכ"ד]. עיין: מודיליאנו, יוסף בן שמואל. על ה"קונטרס" של ר' משה סופר מספר המחבר במכתבו לר' צבי חיות מיום כז במרחשוון תקצ"ח (נדפס בסוף ספרו דרכי הוראה, זאלקווא תר"ג): זה איזה שנים, יצאו איזה קונטרסים מתשוב[ו]תי וחידושי על ידי רב אחד מהו' מרדכי שלאנק בהדפיסו ספרי רמב"ן על קידושין ור"י בן מג"ש על שבועות, היה בידו העתקות מחידושי והדפיסם סוף דבריהם, תהלתו באונם ולבסוף ברצוני, כי לא היה פה עמדי כי אם בפראג.