When listing the specific laws of war, the Torah states, “Mi HaIsh HaYareih VeRach HaLeivav Yeileich VeYashov LeVeito,” “Who is the man who is fearful and fainthearted? Let him go and return to his house” (Devarim 20:8). In an attempt to further understand this rule, Rashi explains that the reason such a man would be afraid is because he is scared that his sins will cause Hashem to kill him in war. Chazal specify that the sin he committed could even be that of speaking between putting on his Tefilin Shel Yad and Tefilin Shel Rosh. It is prohibited to distract one’s focus from the Mitzvah of Tefilin while putting them on, and it is his failure to focus that is the source of his fear. Although speaking while putting on Tefilin doesn’t seem like a major transgression, it is obvious from here that it is enough of a sin which, if transgressed, warrants fear of death. The question is, why is this sin so significant that one can be killed for committing it?
Rav A.L. Scheinbaum, in his book Peninim Al HaTorah, retells a speech that Rav Yaakov Galinsky delivered at a Bar Mitzvah celebration. Rav Galinsky poses a simple question: Why is one who has turned thirteen and accepted upon himself the Mitzvot called a “Bar” Mitzvah, while one who sins is known as a “Ba’al” Aveirah? Both “Bar,” which means “son,” and “Ba’al,” which means “owner,” are terms which describe one’s status: A Bar Mitzvah is a son of Mitzvot, since he is now obligated in Mitzvot, and a Ba’al Aveirot is an owner of Aveirot. Why, then, is “Bar” used specifically for Mitzvot, and “Ba’al” specifically for Aveirot?
Rav Galinsky points out a very simple difference between “Bar” and “Ba’al.” “Bar” is a word used to describe a connection that can never be cut off or discontinued, for example, a parent-child relationship. “Ba’al,” on the other hand, is a word used to describe a connection that is not eternally bonded, for example, a husband-wife relationship. Though the connection may be strong, it is able to be severed with divorce. It is for this reason that a child who reaches the age of thirteen and acquires the responsibility of Mitzvot is known as a “Bar” Mitzvah. From that point on, he has a special, unbreakable bond with the Torah. No matter where he goes in life, his obligation to adhere to the commandments of Hashem will always be with him. With regard to a person who sins, he is called a “Ba’al” Aveirah since his connection with sin is able to be broken with Teshuvah and atonement. Nobody is forever bound to sin. Every Jew always has the ability to return to Hashem and his Mitzvot.
Rav Galinsky also presents a key difference between Torah and Chochmah, wisdom. Torah is a guidebook; it teaches us how to live our lives. It is impossible to study Torah properly without incorporating it into everyday life. Chochmah is different. One who possesses wisdom may not necessarily incorporate it into his life.
Rav Galinsky then explains what the Tefilin Shel Rosh and Tefilin Shel Yad represent. The Tefilin Shel Rosh represents thought and belief, while the Tefilin Shel Yad represents actions.
Putting these three concepts together, Rav Galinsky answers the question of why it is crucial to avoid speaking between putting the Tefilin Shel Yad and Tefilin Shel Rosh. When someone becomes a Bar Mitzvah, he gains an unbreakable bond with Hashem, which obligates him to perform Mitzvot such as putting on Tefilin. When one puts on both the Tefilin Shel Yad and Tefilin Shel Rosh together, he is symbolically joining his beliefs (represented by the Shel Rosh) and his actions (represented by the Shel Yad). Just as Torah is impossible to study without it having real world application, one must connect his beliefs to his actions with a bond equally unbreakable. If one speaks between putting on the Tefilin Shel Yad and the Tefilin Shel Rosh, he is demonstrating that his observance is not in harmony with his mindset, and such a person is unfit to represent the Jewish nation on the battlefield. It is for this reason that someone who speaks between putting on his Tefilin Shel Yad and Tefilin Shel Rosh needs to fear for his safety, and is therefore permitted to remain home during times of war.