פירוש על עבודה זרה 71:8

The Talmud cites a counter tradition. The food products made by Gentiles were prohibited not by Daniel, but during the period of Hillel and Shammai when they made “18 decrees.” The discussion of these decrees is found in the beginning of Tractate Shabbat.
The Talmud rejects the notion that Daniel made the decrees, it was rejected, and then Hillel and Shammai remade it. If that was true, why would Rav have said that Daniel made the decree? After all, it was rejected.