Numbers 10:25

מאסף לכל המחנת [THEN THE BANNER OF THE CAMP OF THE CHILDREN OF DAN SET FORWARD] WHICH WAS 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 (i. e. was more numerous than each of the other tribes, except Judah which marched on the front, cf. Chapter II), it marched in the rear so that if anyone of the other tribes lost anything, he (Dan) restored it to him. (מאסף לכל המחנת therefore means “the one who gathered in everything belonging to all the camps”.) — 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”.

וְנָסַ֗ע דֶּ֚גֶל מַחֲנֵ֣ה בְנֵי־דָ֔ן מְאַסֵּ֥ף לְכׇל־הַֽמַּחֲנֹ֖ת לְצִבְאֹתָ֑ם וְעַ֨ל־צְבָא֔וֹ אֲחִיעֶ֖זֶר בֶּן־עַמִּישַׁדָּֽי׃

And the standard of the camp of the children of Dan set forward, which was the rearward of all the camps throughout their hosts: and over his host was Aĥi῾ezer the son of ῾Ammishadday.