John Gill Commentary Joshua 7:10

"And Jehovah said unto Joshua, Get thee up; wherefore art thou thus fallen upon thy face?" — Joshua 7:10 (ASV)

And the Lord said to Joshua, get you up
From the ground where he lay prostrate, with his face to it: this he said, not as refusing his supplication to him, but rather as encouraging and strengthening him; though chiefly he said this in order to instruct him, and that he might prepare for what he was to do:

why do you lie thus upon your face ?
in this manner, so distressed and dejected; or for this thing, as the Targum, for this defeat of the army; something else is to be done besides prayer and supplication.