Sunan Ibn Majah, Chapter: The Chapters on Medicine

"I heard Abu Ubayy bin Umm Haram, who had prayed with the Messenger of Allah (saw) facing both the Qiblah, saying: 'I heard the Messenger of Allah (saw) say: "You should use senna and the Sannut, for in them there is healing for every disease, except the Sam." It was said: "O Messenger of Allah, what is the Sam?" He said: "Death." (One of the narrators) Amr said: "Ibn Abu 'Ablah said: the 'Sannut is dill." Others said: "Rather, it is honey that is kept in a skin (i.e., receptacle) used for ghee."