On a Sunday morning in Brooklyn, in the regally beautiful and iconic Munkatcher synagogue, hundreds of people are assembled for the morning prayers. The sun, having finally made an appearance from where it’s been hiding this icy-cold winter, is at last pouring its warm light through the high stained-glass windows, illuminating the faces of the congregants. People are swaying slowly, eyes raised in supplication, anticipating the presence of Rabbi Moshe Leib Rabinovich, the Munkatcher Rebbe, who is known for his selfless devotion to all who come asking for a favor, comfort, or advice. I am sitting off to a side between my son-in-law and my first and oldest grandson, who is finally approaching the day of his bar mitzvah.Shimon Beirach Bergstein, or Shimi, as we call him, is thin and slight. The word ‘manhood’ seems over-descriptive for such a young child. He weighed only a few ounces when he was born prematurely, one of three tiny triplets. His body literally fit into the palm of my hand, and had I not been distracted by the living miracle I was looking at, I probably would have keeled over with awe.Now Shimi is sitting with his father and grandfather, waiting for an event he doesn’t fully understand, though he can feel its importance. The personal assistant to the Munkatcher Rebbe ushers us out of the main synagogue and into a small, unadorned office, containing only the Rebbe’s chair, his desk, and three side chairs for us to sit in. He has graciously made time on this Sunday morning to initiate my little grandson into the timeless practice of laying tefillin. Evident in his regal countenance is his royal Hasidic ancestry and his tremendous influence over thousands of people the world over. Countless synagogues and schools bear the name Munkatch, and his followers turn to him for advice on matters personal and halachic on a daily basis.The Rebbe invites Shimi to stand before him, and in a soft voice begins to explain what makes tefillin so important and different than all the other mitzvot. He relates in detail the unimaginable devotion of Jews who devised all kinds of ways to conceal their tefillin on their way to the concentration camps during WWII. Tefillin, he says, represents our people being “tied and bound” to God, never wanting to let go of one another as we move along through life. He gently questions and guides Shimi on some of its basic laws, contrasting the tefillin with the tzitz (head plate) that the kohen gadol (high priest) wore on his forehead at all times in the Temple in Jerusalem, and on which was written the words “kodesh la’shem” (“holy unto God”).Now it is time to begin the actual donning of the tefillin. After asking my son-in-law about his own familial customs, the Munkatcher Rebbe carefully opens Shimi’s tefillin bag, solemnly examining the new set. Shimi raises his left sleeve with the assistance of the Rebbe, who puts the arm tefillin on his upper arm, explaining that it is placed there because it is opposite the heart. Then the Rebbe stands and affixes the head Tefillin, gently tightening and making the blessing together with Shimi. Finally, the Rebbe inscribes a new prayer book with a personal blessing for my grandson. It occurs to me that, through Shimi, I have contributed a link to the chain of Jewish people who have been putting on tefillin for thousands of years. Overwhelmed by this thought, I fight back tears.We all stand. The room is quiet and filled with emotion as the Rebbe takes Shimi’s hand and blesses him with long life, success and all that a young person needs to grow up in a world so challenging to spirituality. I feel a renewed appreciation for the mitzvah of tefillin, and on a more personal level, recognize how the influence of a figure like the Munkatcher Rebbe enriches my spiritual life and everything that is most important to me.Yossi Green is a composer of Jewish music. He lives with his family in Sea Gate, Brooklyn.