"I leave behind for you to Caliphs (two successors), the book of Allah and my progeny. The book of Allah is a rope stretched between the heavens and then earth and my progeny is Ahlul Bayt. The two will not separate from each other until they reach me at the pool of paradise." Note that this isn't the same as the famous hadith where the Prophet (pbuh) refers to them as the thaqalayn, this is a different occasion. On this one he refers to them as the two Caliphs (khalifatain). Let us look at the opinions of the main Sunni hadith scholars: Albani- chain is sahih (authentic) Al Arna'oot- chain is hasan (trustworthy) Tabarani- chain is hasan (trustworthy) Suyuti- chain is sahih (authentic) Found in: Musnad Ahmed ibn Hanbal, Fada'il al Sahaba by Ahmed ibn Hanbal, Manba' al Fawa'id, al Kabir by al Tabarani, Majma' al Saghir by al Suyuti, Aqdain for fadha'il al sharafayn and more... My dear brothers from Ahlul Sunnah, could the Prophet (pbuh) get any clearer?