"When Joshua was by Jericho, he lifted up his eyes and looked, and behold, a man was standing before him with his drawn sword in his hand. And Joshua went to him and said to him, 'Are you for us, or for our adversaries?" (Joshua 5:13, ESV).
The "man" gives a loaded response.
"And he said, 'No, but I am the commander of the army of the LORD. Now I have come," (Joshua 5:14, ESV).
He was not for the Israelites or the people of Jericho. He is the commander of the army of the LORD, and he's here now.
- Civil Duties (Gentle Reformation)