For People Who Think There Was No Historical Jesus

[Confused Ape]

Try here for the complete version of Epiphanius's Panarion.

Thank you for finding it. I've just found the passage and am quoting all of it.

16,8 Nor are they ashamed to accuse Paul38 here with certain fabrications of their false apostles’ villainy and imposture. They say that he was Tarsean—which he admits himself and does not deny. And they suppose that he was of Greek parentage, taking the occasion for this from the (same) passage because of his frank statement, “I am a man of Tarsus, a citizen of no mean city.”39 (9) They then claim that he was Greek and the son of a Greek mother and Greek father, but that he had gone up to Jerusalem, stayed there for a while, desired to marry a daughter of the high priest, and had therefore became a proselyte and been circumcised. But since he still could not marry that sort of girl he became angry and wrote against circumcision, and against the Sabbath and the legislation.

I've been double checking how old the original text is. According to the wikipedia article -

It was written in Koine Greek beginning in 374 or 375, and issued about 3 years later,[2]

Reference 2 is -

^ a b c d e f Williams, Frank; translator. "Introduction". The Panarion of Epiphanius of Salamis, Book I (Sects 1-46). 1987. (E.J. Brill, Leiden) ISBN 90-04-07926-2.

There's also an external link to the original text in Greek but as I can't read Koine Greek I'll have to take their word for it.

What I find fascinating about it all is that you said it's a Jewish tradition and the Ebionites were supposed to have been an early sect of Jewish Christians.