Musnad Ahmad 3555

It was narrated that Abu 'Abdur-Rahman 'Abdullah bin Habeeb said: I heard 'Abdullah bin Mas'ood (رضي الله عنه) attribute it to the Prophet (ﷺ): “Allah has not sent down any disease but He has also sent down a remedy for it; those who know it know it and those who did not know it is not know it.”