‘Take a census of the entire assembly of the Children of Israel according to their families” (Bamidbar 1:2).
This is not the first time Hashem counted the Jews. In the Book of Exodus, He counted the Jews when they left Egypt (Shemos 12:37) simply to see how many Jews had left. He also counted them after the sin of the golden calf to see how many had remained faithful (Shemos 38:26).
Why, when He counts them here, does He count them not only in their totality, but also by their family?
At the first counting the Jews had not yet received the Torah. By the time of the second counting, although they had just received the Torah, they were still fresh off the sin of the golden calf. The second counting was to show how many Jews had remained faithful.
This third counting, however, was under different circumstances. By this point the Jews had integrated the Torah into their lives.
They understood it was the central theme of their role in the world.
Therefore, Hashem in His great wisdom counted the Jews as tribes only after they had received the Torah, thus minimizing the possibility of rivals and factions developing. Once the Torah was given, and there was a unifying force, people understood that one could be a part of a large group (the Jews) while being part of a smaller faction (their tribe), and still be an individual.
When the Jews encamped to receive the Torah, the singular form of the verb “to encamp” is used instead of the plural. This was done to show the Jews this fascinating paradox: one could be part of a group, yet still be an individual. That is our goal as Jews: To remain united by the central importance of the Torah by studying it and keeping the mitzvos, while retaining our individuality in serving Hashem.
In every mitzva lay several possibilities of gaining closeness with Hashem. An example is charity. One could give charity by establishing a free loan society. Another could make a soup kitchen, while a third could start a scholarship fund. Which one is right? They all are different and legitimate ways of expressing oneself through mitzvos. This Shavuos may we merit to receive the Torah anew both as a group and individually.