Hadith about black seed:
Aisha (ra) said that she heard the Messenger (saw) say, “This black seed is a cure for every disease except death. “ [Saheeh al-Bukharee (5687)].
Khalid bin Sa’d (ra) said, “We went out and with us was Ghalib bin Abjar (ra). He fell sick along the way and when we came to al-Madinah, he was sick. Ibn Abu ‘Atiq (ra) came to visit him and said to us, ‘You should use this black seed. Take five or seven (seeds) and grind them then apply them to his nostrils with drops of olive oil on this side and on this side for Aisha (ra) narrated to them that she heard the Messenger (saw) say, “This black seed is a cure for every disease except death.” [Saheeh Sunan ibn Majah (3449)].
Ibn Qaiyum (may Allah have mercy upon him) said, “It has immense benefits and his statement that it is a cure for every disease except death is like the statement of Allah.”