When Israel camped, the tabernacle was to be in the center of the camp.  Joshua 3:4 may indicate that here was to be a thousand yards of space between the tabernacle and the camp of Israel.  Within this thousand yard space, the tribe of Levi camped around the tabernalce.  The priests were on the east, family of Kohath on the south, the family of Gershom on the west and Merari on the north.  After the thousand yard perimenter, on the east side of the tabernacle, the tribes of Issachar, Zebulun and Judah were to camp, with Judah being the lead tribe.  On the south side were the tribes of Gad, Reuben, and Simeon, with Reuben as the lead tribe.  On the west were the tribes of Benjamin and Manesseh, led by the tribe of Ephraim.  On the north were the tribes of Asher and Naphtali, led by the tribe of Dan.
    The tabernacle and the ark of God was to be in the center of Israel’s camp, and when she moved out, the Levites and the tabernacle was to come after Ruben and Judah’s group, again in the center of God’s people.  God lived among His people, and He was to be the center and focal point of their lives.