Rashi on Numbers 4:5/רש"י על במדבר ד׳:ה׳

1ובא אהרן ובניו וגו׳ AND [WHEN THE CAMP SETTETH FORWARD,] AARON SHALL COME, AND HIS SONS, etc. — They shall put every object into its wrapping that is prescribed for it in this section, so that the sons of Kohath should have nothing to do except to carry them.

2בנסוע המחנה WHEN THE CAMP SETTETH FORWARD — When the cloud departed they knew that they were to set out on the journey (see Rashi on Numbers 1:51, and Note thereon).