Josh 5:13

“And so you must beware and exercise great care in order to discern with knowledge the kinds of visions, just as Joshua the son of Nun, when he saw a vision and knew there was temptation in it, immediately asked the one who appeared to him and said, "Are you for us, or for our adversaries?" So, then, the soul progresses when it comes to the place where it begins to distinguish between visions; and it is proved to be spiritual if it knows how to discern them all. That is why, as well, one of the spiritual gifts, given by the Holy Spirit, is mentioned as "the ability to distinguish between spirits."”

“Joshua, the successor of Moses, calls the leader of the heavenly angels and archangels and of the supernal powers and as if he were the power and wisdom of the Father, entrusted with the second rank of sovereignty and rule over all, "prince of the host of the Lord," although he saw him only in the form and shape of a man. At any rate, it is written: "And it came to pass, when Joshua was in the field of the city of Jericho, he lifted up his eyes, and saw a man standing over against him, holding a drawn sword, and he went to him and said: 'Are you one of ours, or of our adversaries?' And he said to him, 'I am prince of the host of the Lord and I have now come.' And Joshua fell on his face to the ground and said to him, 'What does my Lord command to his servant?' And the prince of the Lord said to Joshua, 'Loose your shoe from off your feet, for the place on which you stand is a holy place.' " Here, too, you will perceive from the identity of words that this is no other than he who also spoke to Moses.”

“Divine providence surrounds all persons at all times, but it is not visible except to those who have purified their souls of sin and think about God at all times. To these it is luminously revealed at that time; because when they have undergone great temptations for the sake of truth, then they receive the faculty to perceive sensibly as if with eyes of flesh also when necessary, even palpably, according to the kind and cause of the temptation, as if for greater encouragement.So it was with Jacob and Joshua son of Nun, Hananiah and his companions, Peter and others to whom the form of a man appeared to encourage them and to console their faith.”

“Joshua, the son of Nun, and Daniel bowed in veneration before an angel of God, but they did not adore him. For adoration is one thing, and that which is offered in order to honor something of great excellence is another.”

“Joshua the son of Nun did not see the angel as he is by nature, but an image, for an angel by nature is not visible to bodily eyes, yet he fell down and worshiped, and Daniel did likewise. Yet an angel is a creature, a servant and minister of God, but not God. And they fell down in worship before the angels, not as God, but as God's ministering spirits. Shall I not make images of friends? Shall I not honor them, not as gods but as the images of God's friends? Neither Joshua nor Daniel worshiped the angels they saw as gods. Neither do I worship an image as god, but through the images of Christ and of the holy Theotokos and of the saints, I bring worship and honor to God, because of the reverence with which I honor his friends. God did not unite himself with angelic nature but with human nature. God did not become an angel; he became a man by nature and in truth.”