There is a special intention that must be aimed at putting on tefillin to enslave our thoughts, etc. as the wording in the Siddurim states, and this is the main form and purpose of observing this mitzvah, and in retrospect even if he did not think anything, a simple intention to observe the mitzvot of tefillin came out legally, and anyone who puts on a tefillin is proven by his actions that he intends to observe the mitzvah of tefillin.
Sources:
In the Shoah Reish Halkhut Tefillin [O.H. C. Kaha 95] it was brought forth in their supposition that the Holy One, blessed be He, placed these four verses that contain the unity of His name and the Exodus from Egypt on the arm against the heart, and on the head against the brain, so that we would remember the miracles and wonders that He did with us , that they are teachers of his uniqueness, and that he has the power and the government at the top and at the bottom to do with them as he wishes.
And the soul that is in the brain will be enslaved to God, as well as the heart that is the main source of desires and thoughts, and in this the Creator will be remembered and His pleasures will be diminished forever.
And in the siddurs a special wording is printed that some used to say so as not to forget the main purpose and form of fulfilling this mitzvah.
And the expansion of Devarim in the 19th century and in the 19th century (Skat5) that the main mitzvah of tefillin and its existence depends on the fact that one will dwell during the fulfillment of the mitzvah, as it is written so that the Torah of God will be in your mouth, etc. And that in retrospect, even if not for reason but only for the sake of a mitzvah, he left.
And the 5th Efi' did not specifically refer to anything that the Gach came out, according to what he wrote in the 12th century (S. S. S. K. 66) in the name of the living person, if it is proven according to the matter that the thing is done for the sake of a mitzvah, it came out.
מק"ט התשובה הוא: 5727 והקישור הישיר של התשובה הוא: shchiche.com/5727
