This is the Son of Man who hath righteousness …

This is a very old book….

The older sections of 1 Enoch (mainly in the Book of the Watchers) of the text are estimated to date from about 300–200 BC, and the latest part (Book of Parables) is probably 100 BC.

Various Aramaic fragments found in the Dead Sea Scrolls, as well as Koine Greek and Latin fragments, are proof that the Book of Enoch was known by Jews and early Near Eastern Christians.

Book of Enoch :

https://en.wikipedia.org/wiki/Book_of_Enoch

Who is the Son of Man ? (Bar Enosh in Aramaic)

XLVI. The Head of Days and the Son of Man.
CHAPTER XLVI.

1. And there I saw One who had a head of days,
   And His head was white like wool,
   And with Him was another being whose countenance had the appearance of a man,
   And his face was full of graciousness, like one of the holy angels.

2. And I asked the angel who went with me and showed me all the hidden things, concerning that Son of Man, who he was, and whence he was, (and) why he went with the Head of Days? And he answered and said unto me:

This is the Son of Man who hath righteousness,
With whom dwelleth righteousness,
And who revealeth all the treasures of that which is hidden,
Because the Lord of Spirits hath chosen him,
And whose lot hath the pre-eminence before the Lord of Spirits in uprightness for ever.
4, And this Son of Man whom thou hast seen
Shall raise up the kings and the mighty from their seats,
[And the strong from their thrones]
And shall loosen the reins of the strong,
And break the teeth of the sinners.

1. [And he shall put down the kings from their thrones and kingdoms]
   Because they do not extol and praise Him,
   Nor humbly acknowledge whence the kingdom was bestowed upon them.
2. And he shall put down the countenance of the strong,
   And shall fill them with shame.
   And darkness shall be their dwelling,
   And worms shall be their bed,
   And they shall have no hope of rising from their beds,
   Because they do not extol the name of the Lord of Spirits.

Source: The 1st Book of Enoch,