Concerning the Zohar and Other Matters

 https://seforimblog.com/2012/08/concerning-zohar-and-other-matters/?print=print

In the article I cited Bruriah Hutner-David who brings the following proof that R. Zvi Hirsch Chajes rejected the traditional authorship of the Zohar: In order to show that the Targum to Ecclesiastes should be dated to the geonic period, Chajes notes that while the angel Raziel is mentioned in this Targum, he is not mentioned in talmudic literature. Hutner-David notes that Raziel is mentioned in the Zohar, a fact that Chajes was presumably aware of, meaning that he was hinting that the Zohar is also a late work.

This is important information, as Emden confesses that his attack against the Zohar was only designed to pull the wool out from under the Sabbatians, whose ideology was linked to the Zohar. The man who wrote to Or Torah, not knowing anything about Rosenberg, asked for help from the readers. He tried to locate the book Tzur Devash quoted by Rosenberg, but was unable.

the following paragraph  appears in an essay by R. Aryeh Kaplan

One of the first things I discovered was that it was written some 20 years after Rabbi Yitzchok investigated the Zohar. He openly, and clearly and unambiguously states that the Zohar was written by Rabbi Shimon bar Yochai. This is something not known to historians, and this is the first time I am discussing it in a public forum. But the fact is that the one person who is historically known to have investigated the authenticity of the Zohar at the time it was first published, unambiguously came to the conclusion that it was an ancient work written by Rabbi Shimon bar Yochai.