The Oral Torah

"My opponent cites no sources saying that orlah does not mean foreskin..."The main reason I haven't is because the two sources I know, namely Rashi and Judah Leow ben Bezalel, are both rabbinical, and I thought citing them (in Hebrew, of course, since no English translation of them is available AFAIK) wouldn't be of much use since you'll most likely say they are not authoritative or biased. But since you didn't have a problem linking to a Karaite website, I suppose I may as well indulge in it. Loew's Tif'eret Yisrael, 19. And while I do suppose that you'll still doubt the authority of that, keep in mind my lengthy post deconstructing the word's use in the Bible. It doesn't solely refer to the foreskin, and isn't simply a by-extension metaphor for something bad (since it only refers to coverage or sealing, not something else as it would've if it actually were a metaphor). For what it's worth, I'm a linguistics student myself, and I think this analysis is straightforward and correct."The Dead Sea Scrolls contain almost the entire Tanakh..."That is not precise. Namely, the scrolls do include most of the Bible, but note that no fragments of Esther were found. Also, they do include fragments of books such as the Book of Enoch, Tobit, Sirach, etc. that aren't actually part of the modern Tanakh. In fact, the Scrolls if anything challenge any notion of a unified Masoretic text before the destruction of the Temple. Otherwise, you would complain that celebrating Purim is rabbis "adding" to the Biblical text. We do see some vague general consensus when it comes to more ancient books, but books written from after the Babylonian era were much less widely agreed upon. From Wikipedia, "Development of the Hebrew Bible canon".As for Nevi'im - the Torah does establish that the Lord will bring prophets to guide Israel even after the death of Moses, but there were quite a few prophetic texts that didn't make it into the Tanakh, i.e. the Book of Gad the Seer, Baruch, etc. Why should you not accept them and accept Isaiah and Joel instead?"Rabbis...have been appointed by man to teach"Yes, based on their extensive knowledge of the scriptures and their unyielding piety. One must understand that the Jewish Sanhedrin was compiled largely of man-appointed rabbis because of an influx of "prophets" (including, but not limited to, Jesus of Nazareth) that caused an unrest and disunity among the people. Having a group of intellectually (rather than emotionally) oriented sages decide the proper interpretation to the Bible, and serve as an authority equal to that of prophets appointed by G-d, was necessary to secure the continuation of a stable base of Jewish halachic law. No matter how one sees their legitimacy (or lack thereof), it was completely required to "set the record straight" at a time when there were multiple differing opinions by rabbis and "prophets" that only served to confuse the people and prompted them to leave the Mitzvot completely. If not for a strong religious authority, that would likely have happened to the entirety of Jews.No, I do not need to prove that the Oral Torah originated from Moses and Sinai to win the debate. Note that the title debate (which you have started) does not say something like "The Oral Torah is the work of man" or "The Oral Torah cannot be traced back to Moses", but simply "The Oral Torah". I frankly do not believe that it is the word of G-d himself passed down from generation to another. But I do believe it is an unshakably important part of Judaism, and that's what I argue for.