These were the ones chosen from the community, leaders of their ancestral tribes. They were the heads of the thousands of Israel.

The land must be divided by lot; and they will inherit in accordance with the names of their ancestral tribes.

You must send to the battle a thousand men from every tribe throughout all the tribes of Israel.”

No inheritance may pass from tribe to tribe. But every one of the tribes of the Israelites must retain its inheritance.”

“Speak to the Israelites, and receive from them a staff from each tribe, one from every tribal leader, twelve staffs; you must write each man’s name on his staff.

So Moses spoke to the Israelites, and each of their leaders gave him a staff, one for each leader, according to their tribes – twelve staffs; the staff of Aaron was among their staffs.