This verse was revealed to the Prophet ﷺ, "Allah only desires to remove impurity from you, people of the household, and to purify you completely" [Ahzab 33:33], in the house of Umm Salama. The Prophet ﷺ called Fatimah, Hasan, and Husayn, and covered them with a cloak, while Ali was behind him, so he covered him with the cloak as well. Then he said, "Allah, these are the people of my household, so remove impurity from them and purify them completely."Umm Salama asked, "And am I with them, Messenger of Allah?"He replied, "You remain in your place, and you are headed toward goodness."
نزلت هذه الآية على النبي ﷺ: {إنما يريد الله ليذهب عنكم الرجس أهل البيت ويطهركم تطهيرا} في بيت أم سلمة، فدعا النبي ﷺ فاطمة وحسنا وحسينا فجللهم بكساء، وعلي خلف ظهره فجلله بكساء، ثم قال: اللهم هؤلاء أهل بيتي فاذهب عنهم الرجس وطهرهم تطهيرا قالت أم سلمة: وأنا معهم يا رسول الله؟ قال: أنت على مكانك وأنت إلي خير.
Tirmidhi (3787, 3205), Tabari in his Tafsir (19/106), and Tabarani in Al-Kabir (8295) all narrated it through Muhammad bin Sulayman bin Al-Asbahani, from Yahya bin Ubayd, from Ata bin Abu Rabah, from Umar bin Abu Salama, who said, and then he mentioned it.Its chain is hasan because of Muhammad bin Sulayman bin Abdullah Al-Kufi, Abu Ali bin Al-Asbahani, for there is disagreement about him, though his hadith is hasan when he does not err, and it appears he did not err here, since there are sahih supporting narrations. Yahya bin Ubayd is Al-Makki, as Tabarani stated explicitly, and he is trustworthy.