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 under his standard.

Numbers 10:14

10:14 The standard of the camp of the Judahites set out first according to their companies, and over his company was Nahshon son of Amminadab.