The Bar Mitzvah, the day a Jewish boy turns thirteen, is a turning point in his life. He comes of age, becoming responsible for adherence to the Mitzvot and fully accountable for his actions and every one celebrates. Chabad Chasidim mark this milestone by having the Bar Mitzvah boy publicly deliver a discourse, originally delivered by Rabbi Shalom DovBer Schneersohn, fifth Lubavitcher Rebbe, on the occasion of his Bar Mitzvah in 5634 (1873). The discourse`s main theme is the cosmic impact of performing the mitzvah of tefillin, and the special connection between this mitzvah and the age of Bar Mitzvah.