Spiritual Tools: Rav Menachem Mendel of Vitebsk: Mitzvah
Fear regarding a mitzvah may occur when one considers that the act of the mitzvah is a divine matter. When one begins to perform the mitzvah by means of his physical limbs, and the paraphernalia of the mitzvah which are also material, one’s spirit is depressed and agitated in that he is reducing divinity to the level of the physical. It is, then, God corporeal, heaven forbid?
Even though man experiences this anxiety from time to time, he is strengthened in his faith in God through the performance of the mitzvah. This is so because the mitzvah blinds him to God, for the words of the living God issue from the Supernal Will that spoke them, and His will is effected down to the very end of the end of the chain of spiritual dissent, to the lowest level. He understands that the Divine Presence is enveloped in the mitzvah for, as is known, every mitzvah concerns the Divine Presence, and the Divine Presence is invested in physical objects by virtue of the mitzvah in which his limbs are involved. They are bound together through the dissent of the attributes.
How does this binding take place? The word mitzvah which is usually translated commandment also implies binding. This binding occurs by means of intellect and the understanding which one in fuses into the mitzvah because of the fear and trembling with which one is gripped lest he reduce divinity to mere physicality.
This fear, however, does not cause him to lose his faith, for he draws love and joy, which are derived from the attributes in the contemplation of God’s greatness and His great mercies, from the blessed effluence of the Ein Sof and the Supernal Will, as the Divine Presence is enclothed in the lowliest of existence to bind and unite it with Himself, so that they become one in complete attachment.
However, this can only be achieved after experiencing the preliminary fear. This is so because the pleasurable traits and the joy which one brings upon oneself, in the belief that He wills it so, are not authentic and it is only in his imagination that they can be compared to genuine joy, unless fear of God precedes them, thereby strengthening his faith.
Thereafter, the love or joy or any other such quality which derived from this faith, is authentic, for this is what constitutes the Holy Spirit.
For this reason it is mentioned several times in the Zohar and also the Talmud (Shabbat 31b) that fear must precede the performance of a mitzvah; if it does not, the act is meaningless, and not of the Holy Spirit. (Peri Ha-Aretz; Noach)