Reading the Qur'an While Lying on a Bed
Question :
While I am lying down ready to go to sleep, may I read the Qur'an?
Answer:
Yes, it is allowed for one to recite while lying on a bed except while Junub (in a state of sexual impurity), in which case he may not recite from the Qur'an until having performed Ghusl.
Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 7 Pages 61