The registration according to clans (Numbers 1:18) would have served several purposes. The most immediate purpose is military—so that the armies of Israel would be ordered according to their tribes. Registration according to clans would have brought other benefits, such as knowledge of how the people were related to each other, which would have been necessary for the fulfillment of a number of laws and the allotment of territory.
17 Moses and Aaron took these men who had been named,