A machlokes Rishonim regarding hesech ha’da’as with tefillin. A question on the Rambam’s opinion. An answer based on an important principle of hesech ha’da’as. Explaining the machlokes between the Rambam and Rabbenu Yona based on a discussion as to the definition of hesech ha’da’as. Summing up the basis of the machlokes between the Rambam and Rabbenu Yona. A slightly more involved drasha, but pleasant.