Son of Man, comes from the ancient book of Enoch 1 and the Aramaic Book of Daniel.

In Aramaic it is Bar Enosh…. Son of Man.

As I looked on, in the night vision, one like a Son of Man (Bar Enosh) was coming with the clouds of heaven; he reached the Everlasting One and was presented to him. Dominion, glory, and kingship were given to him. All peoples and nations of every language must serve him. His dominion is an everlasting dominion that shall not pass away, and his kingship, one that shall not be destroyed.”

Dan7:13-14

This “Son of Man” is the divine YHVH Himself walking on the earth among men.

Dig deeper. The Truth awaits you.

1 Enoch raises the "Son of Man" to the same level equal to God, making him co-eternal with him, "When they see that Son of Man sitting on the throne of his glory... For from the beginning the Son of Man was hidden, and the Most High preserved him in the presence of his might, and revealed him to the elect" ( 1 Enoch, 62:5-7); or, "For the Lord of spirits has given (them) to him and has glorified him" ( 1 Enoch, 51:5).