Once i was in sermon with a very pious man, he was telling me that, every night, Allah Subhan.o.tala, comes to the 1st sky and ask the man-kind that if anyone needs Riza, Shifa, Mughfarat… and whoever asks for it in that time is granted with the same…
the way is, get ready to pray, offer 2 nawafil, from the depth of your heart ask for His mercy, ask for cure from the illness…