There is a document in the Dead Sea Scrolls known as the Aramaic Apocalypse (4Q246).
You can read the full (surviving) text here, along with some commentary.
The parts that I would like to call attention to are these:
He will be called the Son of God, and they will call him the Son of the Most High, like a shooting star [Col. 2, Line 1].
Their kingdom will be an eternal kingdom, and their paths will be righteous [Col. 2, Line 5]
Any of that sound familiar?
How about:
And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus.
He will be great, and will be called the Son of the Most High;
and the Lord God will give to him the throne of his father David,
and he will reign over the house of Jacob for ever;
and of his kingdom there will be no end” [Luke 1:31-33]
It’s no surprise, then, that many scholars view the Aramaic Apocalypse as referring to a messianic figure.
An additional piece of evidence is that it compares the Son of God/Son of the Most High to a shooting star. The symbol of a star was also connected with the Messiah.
The interesting thing to me is that it’s another illustration about how ideas found in Christianity (such as the identification of the Messiah with the Son of God) were already found elsewhere in first century Palestinian Judaism.
They may not have understood that the Messiah would be the Son of God in the same sense that Christians came to, but the linkage was already there.