‘Abdullah b. Mas’ûd – Allah be pleased
with him – said:
The believer sees his sins as if he is
sitting at the foot of a mountain fearing that it might fall on him, while the
sinner (fâjir) sees his sins as a fly that lands on his nose, he just waves it
away.
Al-Bukhârî, Al-Sahîh, The Book of Supplications, Chapter on Tawbah.
Ibn Hajr
quotes in his commentary, Fath Al-Bârî:
Ibn Abî Jumrah said, “The reason for
this [fear] is that the heart of
a believer is illuminated; so when he sees from himself something that goes
against what he illuminates his heart with, it is very distressing to him. The wisdom behind giving the example of a
mountain is that a person might find some way to escape from other dangers, but
if a mountain falls on a person he does not survive.
In short, the believer is dominated by fear (of Allah) due to the
strength of îmân he has; he does not therefore feel falsely secure about being
punished because of his sins. This is the way of the Muslim: he always fears
and checks on himself, his good deeds are little to him and he fears even
the small bad deeds he has done.”
~