Joshua 11:15 As the LORD commanded Moses his servant, so did Moses command Joshua, and so did Joshua; he left nothing undone of all that the LORD commanded Moses.
God had told Moses what to do. Moses told Joshua what to do. Joshua had obeyed. He did everything he was told to do by God through Moses. That is a wild statement.
I struggle with obedience. I know what God wants and yet often seem to have an attitude about obeying. I get my directions directly from the Word of God. Joshua was told what God wanted by Moses, and yet he obeyed.
We rebel at the thought of submission, obedience to another person as being above the call of duty. Yet that is pretty much what I see in this verse.