Joshua 3:6

And Joshua spake unto the priests, saying, Take up the ark of the covenant, and pass over before the people. And they took up the ark of the covenant, and went before the people.

Joshua spake unto the priests. This order to the priests would be given privately; and involving, as it did, an important change in the established order of march, it must be considered as announced in the name and by the authority of God. Moreover, as soon as the priests stepped into the waters of the Jordan, they were to stand still. The ark was to accomplish what had been done by the rod of Moses.