WHY DO WE NEED A SEPERATE PASUK TO TEACH US THAT MIDRASHOS ARE ASUR (ES KOL HACHUKIM), THE ONLY REASON MIDRASHOS ARE ASUR IS BECAUSE IT CONTAINS HORAAH, AND WE KNOW HORAAH IS ASUR FROM THE PASUK U'LHOROS.
moshe, brooklyn, U.S.A.
It is possibly for this very reason that the Maharsha says that it seems more likely that the explanation of "Midrashos" is any Derashah that uses the Yud Gimmel Midos that the Torah is Darshened through. However, the Yad Binyamin defends Rashi by saying that Midrashos refers to a Halachic class where the results are not supposed to be practical (Halachah l'Ma'aseh) but informative. This is also forbidden for someone who is Shasuy.
All the best,