The Month of Elul Corresponds to Shevet Gad Who Performed the Mitzvah of Tefillin shel Yad and shel Rosh Meticulously
It with immense satisfaction that we can relate the intense fear of the goyim triggered by the sight of the tefillin shel rosh and the teshuvah we perform in the month of Elul. The Bnei Yissaschar (Elul 1, 8) writes that according to the order of the tribal banners, Elul aligns with shevet Gad. It appears that we can explain the connection between this month and the tribe of Gad based on the berachah Moshe Rabeinu bestowed upon Gad prior to passing away (ibid. 33, 20): "ולגד אמר ברוך מרחיב גד כלביא שכן וטרף זרוע אף קדקוד"—and to Gad he said: Blessed is He Who broadens Gad; he dwells like a lion, and he will tear off an arm as well as a head. Rashi explains: Those whom they killed were recognizable; they would cut off the head with the arm in a single blow.
In Aderes Eliyahu (Devarim), the Gaon of Vilna, zy”a, explains this phenomenon as follows:
"ויש ליתן טעם על זה לפי שאמרו רבותינו ז"ל, סח בין תפלה של יד לתפלה של ראש חוזר מעורכי מלחמה, לפי שיש בה קצת עבירה, והורה לנו כי שבט גד היו צדיקים ביותר והיו נזהרין גם בזה, ולכך זכו להרוג הראש עם הזרוע בפעם אחת, דהיינו הזכות של הראש והזרוע".
We can suggest the reason for this based on the Rabbis’ statement that a person who talks between donning the tefillin shel yad and shel rosh must return from the ranks (of soldiers) on the battlefield, because it is considered a minor aveirah. This shows us that the men of shevet Gad were extremely righteous and were meticulous even in this regard. Therefore, they were capable of killing by severing the head with the arm in a single blow, illustrating their merit regarding the head and the arm.
This explanation was already suggested by the Rosh (end of Maseches Menachos; Hilchos Tefillin 15): "תניא שח בין תפלה לתפלה עבירה היא בידו וחוזר מעורכי המלחמה, שעל שם קיום מצות תפילין ותיקונן, יתקיים באנשי המלחמה וטרף זרוע אף קדקוד". He states that talking between donning the two types of tefillin is an aveirah, and on account of performing the mitzvah properly and precisely, the soldiers were able to kill in this manner.
