Daniel 7:13 -14:
13 As I continued to watch the vision that night, I saw what looked like a son of man coming with the clouds of heaven, and he was presented to the Eternal God.
Dan 7:14 He was crowned king and given power and glory, so that all people of every nation and race would serve him. He will rule forever, and his kingdom is eternal, never to be destroyed.
From this verse the son of man clearly speaks of Jesus the Christ [The Messiah]. Daniel's vision indicates a man that represents both the Eternal Father and the who and what Jesus is [a humble servant],presented in the form of a man. All things being equal,the Son of man is Jesus in human form and at the same time the Son of the Father. [The heavenly One].
Mar 13:26 And then shall they be seeing the Son of Mankind coming in clouds with much power and glory.
My take on this is that Jesus is both God and human and His use of the saying the "son of man" represents a duality of what Jesus is.
John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
Joh 1:14 The Word became a human being and lived here with us. We saw his true glory, the glory of the only Son of the Father. From him all the kindness and all the truth of God have come down to us.
1Jn 4:2 The test by which you may recognize the Spirit of God is that every spirit which acknowledges that Jesus Christ has come as man is from God,
1Jn 4:3 and that no spirit is from God which does not acknowledge this about Jesus.
Mar 10:45 For even the Son of Mankind came, not to be served, but to serve, and to give His soul a ransom for many."
Peace...Mark