Joshua 5:13-15 NIV
Now when Joshua was near Jericho, he looked up and saw a man standing in front of him with a drawn sword in his hand. Joshua went up to him and asked, “Are you for us or for our enemies?”
“Neither,” he replied, “but as commander of the army of the LORD I have now come.” Then Joshua fell facedown to the ground in reverence, and asked him, “What message does my Lord have for his servant?”
The commander of the LORD’s army replied, “Take off your sandals, for the place where you are standing is holy.” And Joshua did so.
NIV: New International Version