John Gill

And the angel of the Lord appeared unto him,.... He stayed some time under the oak, and Gideon being busy in threshing, took no notice of him wherefore he came and stood before him, in his sight: and said unto him, the Lord is with thee; the gracious presence of God was with Gideon while he was threshing, who very probably was sending up ejaculations to heaven, on account of the distressed case of Israel, and was deep in meditation about the affairs of the people of God, and contriving how to deliver them; or the angel might mean himself, who was no other than Jehovah, the eternal Word of God, who was present with him, and spake unto him; and so the Targum,"my Word is thy help:" thou mighty man of valour; who very probably was a stout man in body, and of a courageous mind naturally, and might at this instant have an increase both of bodily strength and greatness of soul; or, however, this was said to animate and encourage him to do what he was about to be sent to do.