Of course it is all fabrication, in the sense, like other traditions, that collected the words of wisdom, given by who knows who, to show wise thinking.
Our Gnostic Christian writings have done the same thing and attributed them to the archetypal good man Jesus that came out of our Chrestian beginnings.
The Christian bible did the same thing with wisdom sayings from Jewish, Zoroastrian and other religions of their day. That is why there is nothing really new in Christianity.
I E. There are, what, 6 older traditions that have a character who is from an immaculate conception with gods that died for their flocks.