Sefer Ha’mitzvos Ha’Katzar (the concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
First Section – the Positive Commandments
9. It is a positive commandment to put tefillin on your head.
(*Continued from last week)
Tefillin requires a clean body all the time he is wearing them. Anyone that says Shema without tefillin is like a witness that gives false testimony about himself [because in Shema he states that it is a mitzvah to wear tefillin, yet he does not wear it himself]. And anyone that wears tefillin with a clean body will get longer life as it states (Yeshaya 38:16) "Hashem, by these things you will live." A person is obligated to touch his tefillin while they are upon him so that he does not take his mind off of them for one moment, because their holiness is very great. All of the time that the tefillin is on his arm and his head, he should be humble and in fear of Heaven and not be engaged in laughter or idle conversation and not think evil thoughts, but should turn his heart to words of truth.
The mitzvah of tefillin applies in all places and at all times, for men but not for women.