Musnad Ahmad 30:1397

'Affan narrated to us, Yazid bin Zuray' narrated to me, Ma'mar narrated to us, from al-Zuhri, from Abu Salamah, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "You must use this black seed, for indeed in it is a cure for everything."