Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

Moses and Aaron, who were commanded to number, or rather to muster, the people, were to have with them "a man of every tribe, who was head-man of his fathers' houses," i.e., a tribe-prince, viz., to help them to carry out the mustering. Beth aboth ("fathers' houses"), in Num 1:2, is a technical expression for the subdivisions in which the mishpachoth, or families of the tribes, were arranged, and is applied in Num 1:4 according to its original usage, based upon the natural division of the tribes into mishpachoth and families, to the fathers' houses which every tribe possessed in the family of its first-born. In Num 1:5-15, these heads of tribes were mentioned by name, as in Num 2:3., Num 7:12., Num 10:14. In Num 1:16 they are designated as "called men of the congregation," because they were called to diets of the congregation, as representatives of the tribes, to regulate the affairs of the nation; also "princes of the tribes of their fathers," and "heads of the thousands of Israel:" "prince," from the nobility of their birth; and "heads," as chiefs of the alaphim composing the tribes. Alaphim is equivalent to mishpachoth (cf. Num 10:4; Jos 22:14); because the number of heads of families in the mishpachoth of a tribe might easily amount to a thousand (see at Exo 18:25). In a similar manner, the term "hundred" in the old German came to be used in several different senses (see Grimm, deutsche Rechts-alterthmer, p. 532).