Joshua 5:13-15

Now it came to pass when Joshua was near Jericho that he lifted up his eyes and looked, and behold, there was a man standing in front of him with his sword drawn in his hand. Joshua approached him and said to him: “Are you for us or for our adversaries?” “Neither,” he said. “Rather, I have now come as commander of ADONAI’s army.” Then Joshua fell on his face to the ground and worshipped. Then he asked him, “What is my lord saying to his servant?” Then the commander of ADONAI’s army replied to Joshua, “Take your sandal off of your foot, for the place where you are standing is holy.” And Joshua did so.