It is known that if you drink alcohol, your prayers aren’t accepted for 40 days. Does that ruling apply to smoking marijuana?
Shaikh ul-Islam Ibn Taymiyyah rahimahullah said: “So whoever becomes intoxicated due to drinking an intoxicant or cannabis, then it is not allowed for him to come near the masjid until he becomes sober. His prayer is not accepted until he knows what he is saying and it is necessary for him to wash his mouth, hands, and clothes from this and this [i.e intoxicants and cannabis]. Prayer is an individual obligation; however, it is not accepted until he repents for forty days as the Prophet sallahu alayhi wa salam said:
“Whoever drinks Khamr, Salat is not accepted from him for forty days. If he repents, then Allah will accept his repentance”
[Graded al-Albani Hasan li Gharihi by al-Albani in Takhreej al-Mishkaat no. 3570]
[Majmoo’ al-Fatawa (37/206)]
This has been extracted from the pamphlet on the prohibition of cannabis as can be seen here.
Faisal Ibn Abdul Qaadir Ibn Hassan