The Prophet ﷺ said, "Allah has not sent down any disease without also sending down a cure for it. Some have come to know it, and some remain ignorant of it."
عن النبي ﷺ قال: ما أنزل الله داء إلا أنزل له شفاء، علمه من علمه، وجهله من جهله.
Ibn Majah narrated it (3438), as did Ahmad (3578) and Hakim (4/399), all of them via Sufyan Thawri, from Ata bin Saaib, from Abu Abdul-Rahman Sulami, who said, "Ibn Masud informed us," and he related it.Ibn Hibban graded it sahih (6062) and narrated it through another route from Ata bin Saaib. Its chain is sahih, because Sufyan Thawri was among those who narrated from Ata bin Saaib before his memory became confused, and others corroborated him by narrating from Ata bin Saaib even though they had heard from him after his memory became confused. This shows that Ata was not confused in narrating this particular hadith. Some also narrated it from Ata bin Saaib stopping it at the companion, but the ruling belongs to those who trace it back to the Prophet.Hakim said, "Its chain is sahih, though the two of them did not include it. The foundational hadith in this chapter is the hadith of Usama bin Sharik, which the two sheikhs criticized on the grounds that they could not find any narrator from Usama bin Sharik other than Ziyad bin Alaqa." That is what he said, end of quote, so he claimed!It is well known, however, that it is not a condition of the two sheikhs that every hadith have more than one corroborating narrator, for Daraqutni answered this claim of his by noting that the two sheikhs, or one of them, included hadiths in their two Sahihs that had only a single corroborating narrator, and he cited examples of this. See Mustadrak (4/401).Similar in meaning is what was narrated from Abu Darda, who said that the Messenger of Allah ﷺ said, "Allah sent down both the disease and the cure, and He made for every disease a cure, so seek treatment, but do not seek treatment through anything unlawful." Abu Dawud narrated it (3875). Its chain includes Thalaba bin Muslim Khathami Shami, who is unknown, and no one other than Ibn Hibban vouched for him as reliable.Similar in meaning too is what was narrated from Abu Saeed Khudri, that the Prophet ﷺ said, "Allah never sent down a disease, or never created a disease, without sending down, or creating, a cure for it, known to whoever knows it and unknown to whoever does not, except for sam." They said, "O Messenger of Allah, what is sam?" He said, "Death."Bazzar narrated it in Kashf Astar (3016), as did Hakim (4/401) and Tabarani in Awsat (1587), all of them from the hadith of Shabib bin Shayba, who said, "Ata bin Abu Rabah narrated to us," who said, "Abu Saeed narrated to us," and he related it. The wording given is Hakim's.Shabib bin Shayba is daif according to the majority of scholars, and he erred in this hadith. Bazzar faulted the hadith on this basis, saying, "It contains Shabib, from Ata, from Abu Saeed, whereas Umar bin Saeed bin Abu Husayn said, from Ata, from Abu Hurairah, from the Prophet ﷺ." End of quote.I say, this is just as he said, and the hadith of Abu Hurairah has already been mentioned at the beginning of the chapter.