Parashat Bamidbar begins with the census that God commanded Moshe to conduct at Mount Sinai approximately one year after the Exodus. Many writers addressed the question as to the purpose of the census, in consideration of the fact that a census had been taken just several months earlier. As we read towards the end of Sefer Shemot (38:25-28), the men among Benei Yisrael were commanded to donate a half-shekel of silver which served both as a means of counting the nation, and to provide the silver needed for the construction of the Mishkan. Now, just several months later, Benei Yisrael are counted again, and the obvious question arises as to why this was necessary. Rashi, in his opening comments to Sefer Bamidbar, writes based on the Midrash that God, in His great love for Benei Yisrael, wanted them to be counted at every significant moment during this early, formative period of their history. He thus ordered that they be counted in preparation for the Mishkan’s construction, which took place after the sin of the golden calf, and now, after the Mishkan was completed and He was establishing His residence among them, He wanted an additional census conducted.
Da’at Zekeinim cites a different answer from Rabbenu Yosef Bekhor Shor, who noted that there was a fundamental difference between the two censuses. At the end of Sefer Shemot, a simple census was taken of the entire nation, while here, in Parashat Bamidbar, the census was taken by tribe. In addition to determining the total number of men in the nation, the census here also counted the population of each individual tribe, as God was now commanding the nation to arrange itself according to tribe around the Mishkan during travel and encampment. Thus, this second census did not simply repeat the first, and it served a different purpose.
We might add that indeed, tribal identity seems to emerge as an important theme in the early part of Sefer Bamidbar, where the Torah tells of Benei Yisrael’s preparations for travel. The book begins with God naming the tribal leaders who were to assist Moshe and Aharon in conducting the census, right away setting a tone of tribal affiliation. We then read the results of the census, which are presented on a tribe-by-tribe basis, and are followed by the description of the nation’s arrangement during encampment and travel, emphasizing each tribe’s population and leader, and that each tribe had its own unique banner. The development of this theme might also answer the question many have asked concerning the special offerings brought by the tribal leaders on the occasion of the Mishkan’s inauguration, which the Torah tells later, in Parashat Naso (chapter 7). Seemingly, this section should have appeared in Sefer Vayikra, specifically, in Parashat Shemini, which tells of the events that took place at the time of the Mishkan’s consecration. The answer, perhaps, is that the theme of tribal affiliation is developed specifically here, in Sefer Bamidbar. Throughout Sefer Shemot and Sefer Vayikra, there is very little mention of the different tribes of Israel; the Torah speaks of Benei Yisrael as a single entity, with only the kohanim being designated for a unique status. Now, in Sefer Bamidbar, the Torah seeks to emphasize the individual identities of all the tribes, and so in this context, it highlights the individual offerings brought by each tribal leader, representing his tribe. Each brought an offering on a separate day, because each tribe was now assuming its unique importance and individual quality.
The likely reason for this emphasis here in Sefer Bamidbar has to do with the fact that Benei Yisrael were now preparing for what was to be their journey to Eretz Yisrael. Although they ended up spending forty years wandering in the wilderness, their departure from Sinai was intended to lead them directly to the Land of Israel, a process that was frustrated by a series of mistakes made by the people, particularly, the sin of the spies. After forging their collective national identity at Mount Sinai, joining together to receive the Torah and then again to construct the Mishkan, the time now came for them to forge individual tribal identities in preparation for their residence in Eretz Yisrael. Whereas in Sinai the people encamped altogether at the foot of the mountain, in the Land of Israel they would be dispersed and divided by vast distances. They would, of course, continue maintaining their collective identity through the Beit Ha-mikdash – the successor, so-to-speak, of the Mishkan – but they would also, by necessity, be required to forge individual geographic identities. Members of each tribe would settle in the same region and develop their own unique qualities and subculture within the multicolored fabric of Am Yisrael. In preparation for this inevitable eventuality, Benei Yisrael already in the wilderness were to travel and encamp according to tribes, and to strongly identify with their individual tribes even as they strongly identified with the collective entity of Benei Yisrael. This sense of tribal affiliation was a vital part of the people’s preparations for entering the Land of Israel, where they would live and serve God both as a single nation and as individual communities.