And he said, Nay; but as captain of the host of the LORD am I now come. And Joshua fell on his face to the earth, and did worship, and said unto him, What saith my lord unto his servant? But as captain of the host of the Lord am I now come - By this saying Joshua was both encouraged and instructed. As if he had said, "Fear not; Jehovah hath sent from heaven to save thee and thy people from the reproach of them that would swallow thee up. Israel is the Lord's host; and the Lord of hosts is Israel's Captain. Thou thyself shalt only be captain under me, and I am now about to instruct thee relative to thy conduct in this war."
And Joshua - did worship - Nor was he reprehended for offering Divine worship to this person, which he would not have received had he been a created angel. See Revelation 22:8, Revelation 22:9.