Charles Ellicott Commentary Joshua 1:11

"Pass through the midst of the camp, and command the people, saying, Prepare you victuals; for within three days ye are to pass over this Jordan, to go in to possess the land, which Jehovah your God giveth you to possess it." — Joshua 1:11 (ASV)

Prepare you victuals. —The question may be asked, what preparation is intended, since they had the manna, which did not cease until several days after they passed the Jordan. But it does not seem possible to assign any other meaning to this word except that of provision for a journey or for a warlike expedition. Perhaps the order was intended to prepare the Israelites for the transition from the manna to other food. It may also be that the manna which supported them in their pilgrimage through the wilderness was not as well-suited to sustain them in the warfare which they were about to begin.

For the phrase itself, compare Exodus 12:39: They were thrust out of Egypt, and could not tarry, neither had they prepared for themselves any victual. When there was a difficulty in obtaining other provision, God gave His people manna. Now, when they could easily provide food for themselves, He would not support them in idleness; and perhaps this is the common-sense view of the order given in the text. If called to any expedition which would take them far from the camp, the manna would not be within reach of all.