A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
num 2:2THE 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 ensign only for a tribe would not have been visible at the extremities of so large a body. We possess no authentic information as to their forms, material, colors, and devices. But it is probable that they might bear some resemblance to those of Egypt, only stripped of any idolatrous symbols. These were of an umbrella or a fanlike form, made of ostrich feathers, shawls, &c., lifted on the points of long poles, which were borne, either like the sacred central one, on a car, or on men's shoulders, while others might be like the beacon lights which are set on poles by Eastern pilgrims at night. Jewish writers say that the standards of the Hebrew tribes were symbols borrowed from the prophetic blessing of Jacob--Judah's being a lion, Benjamin's a wolf, &c. [Gen. 49:3-24]; and that the ensigns or banners were distinguished by their colors--the colors of each tribe being the same as that of the precious stone representing that tribe in the breastplate of the high priest [Exo 28:17-21].
far off about the tabernacle of the congregation shall they pitch--that is, "over against," at a reverential distance. The place of every tribe is successively and specifically described because each had a certain part assigned both in the order of march and the disposition of the encampment.
num 2:3on the east side toward the rising of the sun shall they of the standard of the camp of Judah pitch throughout their armies--Judah, placed at the head of a camp composed of three tribes rallying under its standard, was said to have combined the united colors in the high priest's breastplate, but called by the name of Judah. They were appointed to occupy the east side and to take the lead in the march, which, for the most part, was in an easterly direction.
Nahshon--or Naasson (Mat 1:4; Luk 3:32-33).
shall be captain--It appears that the twelve men who were called to superintend the census were also appointed to be the captains of their respective tribes--a dignity which they owed probably to the circumstances, formerly noticed, of their holding the hereditary office of head or "prince."
num 2:5those that pitch next unto him--that is, on the one side.
num 2:7Then the tribe of Zebulun--on the other side. While Judah's tribe was the most numerous, those of Issachar and Zebulun were also very numerous; so that the association of those three tribes formed a strong and imposing van.
num 2:10On the south side the standard of the camp of Reuben--The description given of the position of Reuben and his attendant tribes on the south, of Ephraim and his associates on the west, of Dan and his confederates on the north, with that of Judah on the east, suggests the idea of a square or quadrangle, which, allowing one square cubit to each soldier while remaining close in the ranks, has been computed to extend over an area of somewhat more than twelve square miles. But into our calculations of the occupied space must be taken not only the fighting men, whose numbers are here given, but also the families, tents, and baggage. The tabernacle or sacred tent of their Divine King, with the camp of the Levites around it (see on Num 3:38), formed the center, as does the chief's in the encampment of all nomad people. In marching, this order was adhered to, with some necessary variations. Judah led the way, followed, it is most probable, by Issachar and Zebulun [Num 10:14-16]. Reuben, Simeon, and Gad formed the second great division [Num 10:18-20]. They were followed by the central company, composed of the Levites, bearing the tabernacle [Num 10:21]. Then the third and posterior squadron consisted of Ephraim, Manasseh, and Benjamin [Num 10:22-24], while the hindmost place was assigned to Dan, Asher, and Naphtali [Num 10:25-27]. Thus Judah's, which was the most numerous, formed the van: and Dan's, which was the next in force, brought up the rear; while Reuben's and Ephraim's, with the tribes associated with them respectively, being the smallest and weakest, were placed in the center. (See on Num 10:13).