Shaddad Abu Ammar reported,

I came to visit Wathila bin Asqa while a group of people were with him. They began to speak about Ali, and when they had left, he said to me, "Shall I tell you what I once saw from the Messenger of Allah ﷺ?"I said, "Certainly."He said, "I went to Fatimah to ask her about Ali. She said, 'He has gone to the Messenger of Allah ﷺ.' So I sat waiting for him until the Messenger of Allah ﷺ arrived, accompanied by Ali, Hasan, and Husayn, holding each of the two boys by the hand. When he entered, he drew Ali and Fatimah close and seated them in front of him, then placed Hasan and Husayn each on one of his thighs. He then wrapped his garment, or he said cloak, around them and recited this verse, 'Allah only wishes to remove all impurity from you, people of the household, and to purify you completely' [Ahzab 33:33]. Then he said, 'O Allah, these are the people of my household, and the people of my household are most deserving.'"

عن شداد أبي عمار قال

دخلت على واثلة بن الأسقع وعنده قوم، فذكروا عليا، فلما قاموا قال لي: ألا أخبرك بما رأيت من رسول الله ﷺ؟ قلت: بلى، قال: أتيت فاطمة أسألها عن علي، قالت: توجه إلى رسول الله ﷺ فجلست أنتظره حتى جاء رسول الله ﷺ ومعه علي وحسن وحسين، آخذ كل واحد منهما بيده، حتى دخل فأدنى عليا وفاطمة، فأجلسهما بين يديه، وأجلس حسنا وحسينا كل واحد منهما على فخذه، ثم لف عليهم ثوبه، أو قال: كساء، ثم تلا هذه الآية: {إنما يريد الله ليذهب عنكم الرجس أهل البيت ويطهركم تطهيرا} وقال: اللهم هؤلاء أهل بيتي، وأهل بيتي أحق.