The commander of the Lord's army

“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.” Joshua 5:15
On the eve of the battle of Jericho, Joshua encountered a man outside the camp holding a sword. He challenged him, saying, “Are you for us or for our enemies?” (Josh. 5:13). The man announced, “Neither... but as commander of the army of the Lord I have now come.” (Josh. 5:14).
But this is no ordinary angel. Angels do not demand worship from people, nor do they accept worship from people (see Rev. 19:9-10). This person not only accepts Joshua’s worship, but He demands it. He uses the same words that God used when speaking to Moses from the burning bush: “Take off your sandals, for the place where you are standing is holy” (Josh. 5:15, Ex. 3:5).
This can only be one person: the Son of God, in His pre-Incarnate form. The word ‘angel’ simply means messenger. In this capacity, Jesus is coming to earth Himself to deliver a message – just as He did to Abraham (Gen. 18:1), Hagar (Gen. 16:7, 13), Jacob (Gen. 32:28-30), Balaam (Num. 22:32), Gideon (Judg. 6:12), Manoah and his wife (Judg. 13), Elijah (2 Kin. 1:3-4), and others. It would appear from the text that the message He had come to give Joshua was the strategy for the battle of Jericho – how the Israelites were to march around the city once a day for six days, then seven times around on the seventh day, then to blow the trumpets, at which point the walls would fall down.
This was not a battle that the Israelites fought, as such. Although they killed the inhabitants of Jericho (apart from Rahab and her family), it was God who overcame the city and caused the walls to fall down. In a similar way, God works on our behalf today – if we are faithful to Him, as Joshua was.