‘Allaamah Qastallaani (rahimahullah) mentions the following incident:
Once, I became so ill that the doctors lost all hope of my recovery. This condition of sickness remained for many years.
One day, on 28th Jumadaa Oolaa 893 A.H., while in Makkah Mukarramah, I made du‘aa to Allah Ta‘ala through the waseelah (blessed name) of Rasulullah (sallallahu ‘alaihi wasallam) and begged Allah Ta‘ala to cure me of my sickness. Thereafter, while asleep, I had a dream in which I saw a man with a piece of paper in his hand. On the paper, the following words were written:
“Rasulullah (sallallahu ‘alaihi wasallam) has commanded that this medicine be given to Ahmed bin Qastallaani.”
When I awoke, I was completely cured.
(Fazaa’il-e-Madinah)