It is narrated from Sayyidah Umm Salamah (may Allah be pleased with her); she said: the Messenger of Allah (peace and blessings be upon him) came to me, and Sayyidah Fatimah (may Allah be pleased with her) brought some food in a vessel and placed it before him (peace and blessings be upon him). He (peace and blessings be upon him) said: "Call your husband and your two sons." So they were called, and they began to eat while they were sitting on a Khaybari cloak. Then the Messenger of Allah (peace and blessings be upon him) gathered that cloak over them, then said: "These are the people of my household and my closest ones, so remove impurity from them and purify them thoroughly."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20076