Numbers 2:1

“And the Lord spake unto Moses, and unto Aaron, etc.] Very probably after the number of the children of Israel was taken, of which in the preceding chapter, and when the congregation of Israel with the tabernacle were about to set forward on their journey; and therefore directions are here given for their orderly and regular proceeding in it, in what form and manner they should both encamp and march; saying: as follows.”

“THE ORDER OF THE TRIBES IN THEIR TENTS. (Num. 2:1-34) Every man . . . shall pitch by his own standard, with the ensign of their father's house--Standards were visible signs of a certain recognized form for directing the movements of large bodies of people. As the Israelites were commanded to encamp "each by his own standard, with the ensign of their father's house," the direction has been considered as implying that they possessed three varieties: (1) the great tribal standards, which served as rallying points for the twelve large clans of the people; (2) the standards of the subdivided portions; and, (3) those of families or houses. The latter must have been absolutely necessary, as one…”

“2:1-34 Israel’s camps were to be organized by tribal groupings. This arrangement may have reflected concerns for social status, access to water, and security for the Tabernacle, which represented the Lord’s presence. The Egyptian army from approximately this same era camped in a similar defensive formation to protect the sacred objects that accompanied their field campaigns.”

“Order of the Twelve Tribes in the Camp and on the March. - Num 2:1, Num 2:2. The twelve tribes were to encamp each one by his standard, by the signs of their fathers' houses, opposite to the tabernacle (at some distance) round about, and, according to the more precise directions given afterwards, in such order that on every side of the tabernacle three tribes were encamped side by side and united under one banner, so that the twelve tribes formed four large camps or divisions of an army. Between these camps and the court surrounding the tabernacle, the three leading mishpachoth of the Levites were to be encamped on three sides, and Moses and Aaron with the sons of Aaron (i.e., the priests)…”