NUM 4:15

15 And when Aharon and his banim have made an end of covering HaKodesh, and all the Klei HaKodesh, as the machaneh [(camp)] is to set forward, after that, the Bnei Kehat shall come to bear it; but they shall not touch any kodesh, lest they die. These things are the massa [(burden)] of the Bnei Kehat in the Ohel Mo'ed.