(1) The Eternal spoke to Moses, saying: (2) Have two silver trumpets made; make them of hammered work. They shall serve you to summon the community and to set the divisions in motion. (3) When both are blown in long blasts, the whole community shall assemble before you at the entrance of the Tent of Meeting; (4) and if only one is blown, the chieftains, heads of Israel’s contingents, shall assemble before you. (5) But when you sound short blasts, the divisions encamped on the east shall move forward; (6) and when you sound short blasts a second time, those encamped on the south shall move forward. Thus short blasts shall be blown for setting them in motion,
(14) the first standard to set out, troop by troop, was the division of Judah. In command of its troops was Nahshon son of Amminadab; (15) in command of the tribal troop of Issachar, Nethanel son of Zuar; (16) and in command of the tribal troop of Zebulun, Eliab son of Helon. (17) Then the Tabernacle would be taken apart; and the Gershonites and the Merarites, who carried the Tabernacle, would set out. (18) The next standard to set out, troop by troop, was the division of Reuben. In command of its troop was Elizur son of Shedeur; (19) in command of the tribal troop of Simeon, Shelumiel son of Zurishaddai; (20) and in command of the tribal troop of Gad, Eliasaph son of Deuel. (21) Then the Kohathites, who carried the sacred objects, would set out; and by the time they arrived, the Tabernacle would be set up again. (22) The next standard to set out, troop by troop, was the division of Ephraim. In command of its troop was Elishama son of Ammihud; (23) in command of the tribal troop of Manasseh, Gamaliel son of Pedahzur; (24) and in command of the tribal troop of Benjamin, Abidan son of Gideoni. (25) Then, as the me'asef of all the divisions, the standard of the division of Dan would set out, troop by troop. In command of its troop was Ahiezer son of Ammishaddai;
מאסף לכל המחנת THE GATHERER OF ALL THE CAMPS — The Talmud Yerushalmi Eruvin 5:1 has the following statement: Because the tribe of Dan consisted of numerous troops, it marched in the rear so that if anyone of the other tribes lost anything, he (Dan) restored it to him. — There is one authority that holds that they traveled in formation like a box (i.e. in a military square) and derives this from the text, (Numbers 2:17) “just as they encamp so shall they journey” , and there is another authority that maintains that they traveled in a straight line like a beam, and derives this from the statement that Dan was “the gatherer of all the camps”.
Walking in the Footsteps of the Rearguard, Avital Hochstein, 2017
There is another value expressed in the act of returning objects: retaining, leaving what is inside, within. The tribe of Dan makes certain that anything, and maybe also anyone, that was inside, that formed part of the social fabric, will remain there even at the times of change. The tribe of Dan ensures that things should not be left behind or neglected, even by accident. The tribe of Dan is thus responsible for guarding the internal and its order.
As such Dan represents the view that even during times of change and transition, there is reason to value the past and to re-establish routines, reinstate old patterns, and return objects and values to their rightful place.
פס'. ... ד״א מאסף לכל המחנות שכל מי שנמשך אחריהן (מתקנים) המחנות היה נאסף אל מחנה דן לפי שהיה אחרון...
"As the rear guard of all the divisions" (BeMidbar 10:25) - That anyone who is lagging behind would be included in the camp of Dan because it was the final one.
מאסף כל המחנות, because he was last, and all those who had fallen back for any reason where caught up with the tribe of Dan, therefore he was called me'asef, the gatherer.
Walking in the Footsteps of the Rearguard, Avital Hochstein, 2017
So the space that Dan occupies is not occupied only by people of the tribe of Dan itself. It ends up being a place for everyone, where any member of any tribe might find themselves. Alongside the miraculous order in which Benei Yisrael marched and camped, there is also a bit of disorder according to the Pesikta Zutrata, as the tribe of Dan becomes an all inclusive space. We could imagine someone from the tribe of Yehudah, the head of the pack, who finds the travel difficult - physically or emotionally - and begins walking more and more slowly, even stumbling a little, until he finds himself traveling with the people of the back-most tribe, the me'asef, Dan. It's as if when Dan gathers up all of the people who are travelling, he creates and provides for them someplace to be held and protected from the hardships that they bear with difficulty. Dan would include everyone, those who started in the rear and those who ended up there haphazardly.
For you will not depart in haste, Nor will you leave in flight; For the Eternal is marching before you, The God of Israel is your rear guard.