1. The primary sources of understanding Islam are the Qur'an and the Established Sunnah. Hadith is a valuable source of information but it is not an independent source of understanding Islam.
Therefore no hadith, on its own, adds any essential religious beliefs or practices to the corpus of religion.
2. No understanding of hadith can be against the clear statements of the Qur’an or clear principles that the Almighty has established in the Qur’an.
3. When the Qur’an instructs about a religious practice no hadith can add any compulsory elements to that instruction.
4. No understanding of a hadith can be against known facts.
5. No understanding of a hadith can change the meaning of a verse of the Qur’an from its obvious meaning.
http://www.exploring-islam.com/a-layman ... adith.html
