Isserles’ glosses signaled far more than simply the “Ashkenization” of a Sephardic text; they also heralded the beginning of an extensive commentary tradition that would grow up around Karo’s code, radically transforming its purpose and its material form. In the ensuing centuries, Joshua Falk, Shabbateai (or Sabbatai) ha-Kohen, Abraham Gombiner, Israel Meir ha-Kohen, and many others would eventually add their commentaries to all or part of the Shulhan ‘arukh. In so doing, they transformed the text from a short compendium accessible to anyone with a basic knowledge of Hebrew into one that required instruction and supervision. The book was also transformed in its material form. Already in the sixteenth century, the Shulhan ‘arukh had changed from a being a book that could be carried with ease into a folio volume that required care, attention, and two hands. The commentary tradition that surrounded its text would soon come to dwarf Karo’s own work.
Yaacob Dweck, “What is a Jewish Book?” AJS Review 34:2 (November 2010), 370-371.