The Prophet ﷺ said, "Truffles are a remedy for the eye, the Ajwa date is among the fruits of Paradise, and this black seed," (Ibn Burayda said, meaning the shuniz that is found in salt) "is a cure for every disease except death."
عن النبي ﷺ قال: الكمأة دواء للعين، وإن العجوة من فاكهة الجنة، وإن هذه الحبة السوداء-قال ابن بريدة: يعني الشونيز الذي يكون في الملح-، دواء من كل داء إلا الموت.
Ahmad (22938) narrated it from Aswad bin Amir, who said, Zuhayr narrated to us, from Wasil bin Hayyan Bajali, who said, Abdullah bin Burayda narrated to us, from his father, and he mentioned it.His saying "Wasil bin Hayyan" is a mistake, in which Zuhayr bin Muawiya erred. Ahmad bin Hanbal said, "The name got confused for Zuhayr." Abu Dawud said, "Zuhayr erred in it." The correct name is Salih bin Hayyan Qurashi, also called Qurashi Kufi, who is daif. Bukhari, Abu Hatim, Abu Dawud, and others criticized him.His name is stated explicitly by Ahmad (22972) in a long hadith from Muhammad bin Ubayd, who said, Salih, meaning Ibn Hayyan, narrated to us, from Ibn Burayda, from his father, that he was with the Messenger of Allah ﷺ along with forty-two of his companions, and the Prophet ﷺ was praying at the Maqam, while they sat behind him waiting for him. When he finished praying, he leaned forward between himself and the Kaaba as if he wanted to take something, then he turned to his companions. They started to rise, but he gestured with his hand for them to sit, so they sat.He said, "Did you see me, when I finished my prayer, lean forward between myself and the Kaaba as if I wanted to take something?" They said, "Yes, Messenger of Allah." He said, "Paradise was presented to me, and I had never seen anything like what was in it. A cluster of grapes passed by me and delighted me, so I reached out to take it, but it slipped away from me before I could. Had I taken it, I would have planted it among you so that you could eat from the fruit of Paradise. And know that truffles are a remedy for the eye, and that ajwa dates are among the fruits of Paradise, and that this black seed, the one found in salt, know that it is a remedy for every disease except death."However, the hadith has been narrated by another route. Ibn Abu Shayba (23906) narrated it from Abdul-Rahim bin Sulayman, from Ismail bin Muslim, from Qatada and Matar bin Abdul-Rahman, from Abdullah bin Burayda, from his father, from the Prophet ﷺ, who said, "In the shuniz there is a cure for every disease except death." They said, "Messenger of Allah, what is death?" He said, "Death is death."Ismail bin Muslim is Makki Abu Ishaq, who is daif. Ibn Main, Ibn Madini, Abu Hatim, and others graded him daif.However, the hadith is strengthened through these two chains, since neither contains anyone accused of fabrication, and its individual statements have sahih corroborating narrations.His saying "shuniz" refers to the black seed.