On the intermediate days of Pesach and Sukkot, there is a great debate among the major halachic authorities as to whether tefillin should be worn or not. Some rishonim forbid tefillin to be worn on Chol HaMoed as they consider the days have the same status as a festival which in itself constitutes a “sign” making the laying of tefillin unnecessary. Other rishonim argue and hold that Chol HaMoed does not constitute a “sign” in which case tefillin must be worn on Chol HaMoed. Due to this conflict of opinion there are three existing customs: To refrain from wearing tefillin. The Beth Yosef notes that all Sephardic Jews refrain from wearing tefillin on Chol HaMoed. His ruling is based on kabbalistic reasons. The Zohar strongly advocates refraining from wearing tefillin on Chol HaMoed. Accordingly, the Shulchan Aruch rules that it is forbidden to wear tefillin on Chol HaMoed. This is also the opinion of the Vilna Gaon whose ruling has been universally accepted in Israel. To wear tefillin but to refrain from reciting the blessings. The Tur notes that there are a number of rishonim who are uncertain whether one must wear tefillin on Chol HaMoed and therefore advocates wearing tefillin but refraining from reciting the blessings. The authorities that rule like this include the Ritva, the SeMaG, the Meiri and the Taz. The advantage of this compromise is that one avoids violating very serious transgressions of either not donning tefillin or making a blessing in vain. To wear tefillin and reciting the blessings in an undertone. This is the opinion of the Rama who writes that this is the universally accepted practice among Ashkenazic Jews. The Mishna Berura recommends that on Chol Hamoed one make a mental stipulation before donning tefillin: If I am obligated to don tefillin I intend to fulfill my obligation and if I am not obligated to don tefillin, my doing so should not be considered as fulfilling any obligation; and that the blessing not be recited. The Aruch Hashulchan writes that a practice among some Ashkenazic Jews has developed to refrain from wearing tefillin on Chol Hamoed. He is referring to the practice of Hasidic Jews whose rituals are inspired by kaballah. Interestingly, this was also the practice at the famed Volozhin yeshiva and of Rav Chaim Soloveitchik.

הסכמות: ר' חיים אלעזר שפירא, מונקאטש, ו נצבים וילך תרצ"ג; ר' דוד שליסעל, מונקאטש, ב עקב תרצ"ג; ר' יוסף אלימלך כהנא, אונגוואר, א של סליחות תרצ"ג; ר' דוד דוב מייזליש, אוהעלי, ב ראה תרצ"ג; ר' שמואל אהרן ב"ר נפתלי [מילר], לאבאווא, ה ראה תרצ"ג; ר' יעקב חיים סופר, ירושלים, כא אלול תרצ"ג.