The verse 33:33 was revealed informing about the Infallible progeny of the Prophet (SAWA). Hadith al-Kisaa' stated that the Prophet (SAWA ) kept the kisa (cloak) on Ali (as), Fatima (as), Hassan (as) and Hussain (as) and said: O Allah, theses are my Ahlul Bayt, so keep filth away from them and purify them real purification.. None of the wives of the Prophet was allowed to join them. This authentic Hadeeth is narrated in Sunni books like:
Saheeh Muslim 4450
Musnad Ahmad Ibn Hanbal 2903 and 16374 and 25300 and 25339 and 25383 and 25521 and more.
Tirmithi 3129 and 3130 and 3719 and 3809.
Nasa'ee in Sunan Al-Kubra v.5 p.107 and v.5 p.112
al-Bayhaqi in Al-Sunan al-Kubba v.2, p.149 and v.2 p. 142
It was also narrated in Shia books by:
· Sheikh al-Tusi in his book al-Amaali
· Tafsir al-'Ayyashi
· Tafsir Furat al-Kufi
· Tafsir al-Qummi by Ali ibn Ibrahim
· The book of Sulaym ibn Qays
· Kitab al-Khisal by Sheikh al-Saduq