someone came to Molana Alla O deen that when A momin sits in bad gathering for example of music and of instruments of music he does not feel sleepy and spends whole night as it is, but when he sits in any good gathering of A pious man related to Allah for half an hour then sleep disturbs him, what I the reason of this? 

Hazrat said that when a momin sits in good gathering his soul feels peaceful and he feels sleepy but when he sits in bad gathering then his soul remain agitated all the night for this reason the momin cannot sleep. (Faral raza, Dera Ismail khan)