Holding Fast to the Qur'an and Sunnah
Bukhari :: Book 9 :: Volume 92 :: Hadith 461
Narrated Ubaidullah:
Ibn 'Abbas said, "Why do you ask the people of the scripture about anything while your Book (Quran) which has been revealed to Allah's Apostle is newer and the latest? You read it pure, undistorted and unchanged, and Allah has told you that the people of the scripture (Jews and Christians) changed their scripture and distorted it, and wrote the scripture with their own hands and said, 'It is from Allah,' to sell it for a little gain. Does not the knowledge which has come to you prevent you from asking them about anything? No, by Allah, we have never seen any man from them asking you regarding what has been revealed to you!"