Ahmad bin Ishaq Qummi, representative of Imam Hasan Askari
(a.s.) narrates: I went to the Imam and said: May I be sacrificed on
you, I am worried about a matter and I want to ask you about it. But
so far I did not get the opportunity. His Eminence asked: “What is
it?” I asked: “They narrate that your holy ancestors stated: The
prophets sleep on their back, the believers sleep on their right side,
the hypocrites on the left side and the Satans on their chest.”
His Eminence said: “The tradition is correct.”
I asked: “My master, I cannot sleep on my right side. I have to
sleep on the left side.” He said: “Come to me and keep your hand
under your garment.”
Ahmad says: “I placed my hand under my garment. Imam also
put his blessed hand in my garment and his right hand on my right
side and placed his left hand on my left side and passed his hands
over me three times.” Ahmad says: “After that I was unable to sleep
on my left.
Behaarul Anwaar, vol. 76, p.190
Isbaatul Wilayah (Part One) – Ayatullah AliNamazi Shahroodi (r.a.)