How to Find out if a Hadeeth Is Authentic or Not

A "Hadeeth" (pl. ahaadeeth) is a transmitted saying, action, endorsement, or physical traits and characteristics of the Prophet Muhammad [(sallallaahu `alaihi wa sallam (Peace be upon him)]. Authentic ahaadeeth, together with the Holy Qur'aan, are the primary source of Islamic Law.

Steps

• Determine if the hadeeth is in either of the two Saheehs : Saheeh-ul-Bukhaaree and Saheeh Muslim, which are the most authentic books after the Qur'aan. The most authentic and reliable translations of the two Saheehs are those published by Daarussalaam [Dar-us-Salam.com].

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  Also useful are: SahihAlBukhari.com & SahihMuslim.com
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  If the hadeeth is found in the two Saheehs or either of them, it is authentic except in a few extremely rare cases.
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  If the hadeeth is not found in the two Saheehs or either of them, or its authenticity is still in doubt, the best online resource currently available in English is Hadeeth Encyclopedia [Hadeeth.webs.com] .
  
  
  

Tips

Some resources for those who know Arabic:

Dorar.net/Hadith.php موقع الدرر السنية - تيسير الوصول إلى أحاديث الرسول
AhlalHdeeth.com ملتقى أهل الحديث