5:15 From thy foot - In token of reverence and subjection. Holy - Consecrated by my presence. The very same orders which God gave to Moses at the bush, when he was sending him to bring Israel out of Egypt, he here gives to Joshua, for the confirming his faith, that as he had been with Moses, so he would be with him.
5:13-15 We read not of any appearance of God's glory to Joshua till now. There appeared to him one as a man to be noticed. This Man was the Son of God, the eternal Word. Joshua gave him Divine honours: he received them, which a created angel would not have done, and he is called Jehovah, chap. 6:2. To Abraham he appeared as a traveller; to Joshua as a man of war. Christ will be to his people what their faith needs. Christ had his sword drawn, which encouraged Joshua to carry on the war with vigour. Christ's sword drawn in his hand, denotes how ready he is for the defence and salvation of his people. His sword turns every way. Joshua will know whether he is a friend or a foe. The cause between the Israelites and Canaanites, between Christ and Beelzebub, will not admit of any man's refusing to take one part or the other, as he may do in worldly contests. Joshua's inquiry shows an earnest desire to know the will of Christ, and a cheerful readiness and resolution to do it. All true Christians must fight under Christ's banner, and they will conquer by his presence and assistance.
