‘Abdullah b. Mas’ud – 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 (fajir) sees his sins as a fly that lands on his nose, he just waves it away. “ [Al-Bukhari, Al-Sahih, The Book of Supplications, Chapter on Tawbah]
Ibn Hajr quotes in his commentary, Fath Al-Bari:Ibn Abi 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 iman 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.”
It’s just a small sin?
Bilal b. Sa’d – Allah have mercy on him – said:
“Do not think about how small the sin is, but think about who you have just disobeyed.” [Ibn Al-Mubarak, Al-Zuhd wa Al-Raqa’iq Vol.1 p150.]
allahu akbar