במדבר, פרק י׳, פסוק כ״ה

The journey of the Israelites through the desert was highly organized, with every tribe assigned a specific location and duty. Protecting the back of the massive procession required a special kind of strength to ensure the entire camp remained whole and secure. This responsibility was given to the camp of Dan, who served as the rear guard for the nation. Their role was to bring up the rear, protect the back, and gather all the loose ends into a single, unified group [רש״ר הירש, ביאור יש״ר].

In practice, this responsibility involved two primary tasks designed to protect the community. First, they gathered the stragglers. If anyone from the other tribes became exhausted, fell behind, or simply could not keep up with the pace of their own camp, they would drop back and be welcomed into the camp of Dan. The people of Dan deliberately walked at a slower pace alongside these tired travelers, ensuring that no one was left isolated and exposed in the wilderness [דעת זקנים, העמק דבר, בכור שור, חזקוני]. Second, they recovered lost items. The members of the tribe picked up any objects dropped by the camps ahead of them and returned the belongings to their rightful owners [רש״י, תורה תמימה, צאינה וראינה].

The selection of Dan for this specific job was based on their massive population. While the tribe of Judah was larger in number, Judah carried the authority of royalty, making the front of the procession its natural and necessary place. As the second largest tribe, Dan was positioned at the back to provide the strongest possible rear guard [מזרחי, גור אריה, שפתי חכמים, חזקוני]. Within the camp of Dan itself, the specific tribe that physically walked at the very end, closing the entire march, was the tribe of Naphtali [אבן עזרא].

The exact shape of the marching formation is a subject of broad discussion among commentators. One approach suggests that the Israelites traveled in a straight, single-file line. In this arrangement, since Dan traveled last, they naturally served as the rear guard for everyone. Conversely, another perspective argues that the nation traveled in the exact same square formation in which they camped. This presents a logistical challenge, as Dan's fixed position in the square was on the northern side, rather than the western side which formed the back. To resolve this, commentators explain that due to Dan's enormous population, their people spread out far beyond their northern boundary. They wrapped around the back of the camp of Ephraim in the west, effectively forming a protective barrier across the entire rear of the nation [רש״י, ריב״א, שפתי חכמים, לבוש האורה, משכיל לדוד]. Others suggest that to properly arrange the travel order, the camps may have marched in a diamond shape [ברכת אשר על התורה].