Numbers 2:16-17

2:16 All those numbered of the camp of Reuben, according to their divisions, are 151,450. They will travel second.

The Tribe in the Center

2:17 “Then the tent of meeting with the camp of the Levites will travel in the middle of the camps. They will travel in the same order as they camped, each in his own place ¹  under his standard.

¹ tn The Hebrew expression is עַל־יָדוֹ (’al-yado, “upon his hand”). This clearly refers to a specifically designated place for each man.