Sahih Muslim
The Book on Salutations and Greetings (Kitab As-Salam)
Book Number: 026 / Hadith Number: 5489
Abu Huraira reported that he heard Allah's Messenger (may peace be upon him) as saying: Nigella seed is a remedy for every disease except death. This hadith has been narrated through another chain of transmitters but with a slight variation of wording.