Musnad Ahmad 1156:125

Abu Ahmad al-Zubayri narrated to us, Sufyan narrated to us, from Zubayd, from Shahr ibn Hawshab, from Umm Salamah, that the Prophet, peace and blessings of Allah be upon him, covered Ali, Hasan, Husayn, and Fatimah with a cloak, then said: "O Allah, these are the people of my house and my close kin. O Allah, remove impurity from them and purify them with a thorough purification." Umm Salamah said: I said, "O Messenger of Allah, am I among them?" He said, "You are upon good."