Albert Barnes 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 order was probably given with the knowledge that the manna would cease when the host crossed the Jordan (Exodus 16:35), and possibly because amidst their preparations there might not be opportunity to gather it in sufficient quantity. Nor does it appear that manna ever formed the whole and sole sustenance of the people (Compare to Numbers 20:1 note).

It is the view of the majority of commentators—Jewish and Christian, ancient and modern—that the “three days” here named are identical with those of (Joshua 3:2); and that the command of Joshua in the text was not in fact given until after the return of the spies. Here, as elsewhere in the Hebrew historical books and frequently in the Gospels, the order of time is superseded by the order of thought.

For the purpose of the writer was not historical merely; it was, on the contrary, mainly religious and theoretical. Intending, then, to exhibit God as accomplishing His promises to the covenant-people, he begins by informing us that God gave the word and set Joshua and the host actually in motion to take possession of their inheritance.

Having placed this leading fact in the forefront, he returns to mention in (Joshua 2:0) certain transactions closely relevant to the early stages of Joshua’s conquests, but which had in fact happened before the camp was removed from the plains of Moab and immediately after the expiration of the thirty days’ mourning for Moses (Deuteronomy 34:8).

The order of events was probably the following:

1. 3rd Nisan, the spies are sent out (Joshua 2:1).
2. 6th, the spies return (Joshua 2:23).
3. 7th, the camp is removed from Shittim to the bank of Jordan (Joshua 3:1), and the command (Joshua 1:11) is issued.
4. 10th, the river is crossed (Joshua 4:19).