The Scofield Bible Commentary, by Cyrus Ingerson Scofield, , at sacred-texts.com
Son of man
"Son of man," used by our Lord of Himself seventy-nine times, is used by Jehovah ninety one times when addressing Ezekiel.
(1) In the case of our Lord the meaning is clear: it is His racial name as the representative Man in the sense of (Co1 15:45-47). The same thought, implying transcendence of mere Judaism, is involved in the phrase when applied to Ezekiel. Israel had forgotten her mission.
(See Scofield) - (Gen 11:10); (Eze 5:5-8).
Now, in her captivity, Jehovah will not forsake His people, but He will remind them that they are but a small part of the race for whom He also cares. Hence the emphasis upon the word "man." The Cherubim "had the likeness of a man" (Eze 1:5) and when the prophet beheld the throne of God, he saw "the likeness as the appearance of a man above upon it" (Eze 1:26).
(See Scofield) - (Mat 8:20); (Rev 1:12); (Rev 1:13).
(2) As used of Ezekiel, the expression indicates, not what the prophet is in himself, but what he is to God; a son of man
(b) endued with the Spirit, and
(c) sent of God.
All this is true also of Christ who was, furthermore, the representative man -- the head of regenerate humanity.