Earlier the Levi'im were counted from the age of one month. Why are they now being counted between the ages of thirty and fifty?
Rashi: Because on of the tasks of the Levi'im was the transportation of the dismantled sections of the Mishkan, which required strength, and a person attains his full strength at the age of thirty, and it is at the age of fifty that it begins to wane. 1
Rashi: A fact which Chazal learn from here.
How can we reconcile this Pasuk with the Pasuk in Bamidbar 8:24, which gives the age as twenty-five?