To whom refers in proverbs 30:4 when it talks about "his son"?
It seems to be a series of rhetorical questions.
We can also go to the Hebrew bible to see who is spoken of as "G-d's son".
Clearly it is written that Israel is.
Of course, I guess you think otherwise.
I agree with SMR, the son is Israel. Exodus 4:22: "Israel is My son, my firstborn"