Musnad Ahmad 30:2919

Husayn narrated to us, he said: Shu'bah narrated to us, he said: Qatadah informed me, he said: I heard Hilal ibn Yazid, from the tribe of Banu Mazin ibn Shayban, he said: I heard Abu Hurayrah saying, from the Prophet, peace and blessings of Allah be upon him: "Indeed, this black seed is a cure for everything, except the Sam." And Qatadah said: "The Sam is death."