Talmud commentary of R' Yeshayah d'Trani, of which he composed as many as six editions to some tractates. The author displays stark originality and a quest for truth, as a result of which he often retracts a position he held in an earlier version, at times using a sharp manner of speech. He greatly revered Rashi, calling him "HaMoreh" (The Teacher), but does not hesitate to disagree with him on occasion.