Musnad Ahmad 1156:274

'Affan narrated to us, Hammad ibn Salamah narrated to us, he said: 'Ali ibn Zayd narrated to us, from Shahr ibn Hawshab, from Umm Salamah, that the Messenger of Allah (peace and blessings of Allah be upon him) said to Fatimah: "Bring me your husband and your two sons." So she brought them, and he cast over them a Fadaki cloak. He said: Then he placed his hand upon them, then said: "O Allah, these are the family of Muhammad, so place Your prayers and Your blessings upon Muhammad and upon the family of Muhammad; indeed, You are Praiseworthy, Glorious." Umm Salamah said: So I lifted the cloak to enter with them, but he pulled it from my hand and said: "You are upon good."