According to the book of Numbers in the Old Testament of the Bible, one year after Moses led the Israelites from Egypt during the Exodus, the number of men aged 20 years or older and available to serve in the Israelites' army totalled at 603,550 men. This census was conducted by Moses and the leaders of the 12 Tribes of Israel, with the clan of Judah contributing the largest number of men. However, only 11 of the 12 Tribes were counted, as the men of the Levites were tasked with protecting the tabernacle, which was the central mneeting and worshipping tent of the Israelitres' nomadic society during the Exodus.

According to the book of Numbers in the Old Testament of the Bible, Levite men were exempt from serving in the Israelites' army during the Exodus, and were instead responsible for the transport and care of the tabernacle. In total, there were 22,000 Levite males aged one month or older, and 8,580 of these men were aged 30-50 years and served in the tabernacle.

Moses and his brother Aaron, the leaders of the Israelites, were from the Levite tribe and a descendent of Kohath. The Kohath was the largest of the Levite clans, although the Merari had the largest number of men serving in the tabernacle. According to Numbers, the Kohathites were responsible for carrying the holiest items in the tabernacle; the Gershonites were responsible for carrying the curtains of the tent; and the Merarites were responsible for carrying the tent's frame.