ASSALAM O ALAIKUM!
Allah عزوجل says in Qur’an:
“Allah has set a seal upon their hearts and upon their hearing, and over their vision is a veil. And for them is a great punishment.” [Al Qur’an 2:7]
Hazrat Hazifa رضی اللّہ تعلا عنہ narrates that Muhammad صل اللّہ علیہ وسلم said:
“Mischiefs (fitna) are presented over the hearts like the particles of broken sack. If heart accepts them, a black dot is drawn on it.
If heart does not accept them, a white dot is drawn on it.
The light of this white dot keeps on increasing which enlightens the whole heart. After that no mischief can ever do wrong with it.
Similarly the blackness of the heart (which accepts these mischiefs) keeps on increasing & ultimately the whole heart becomes black & dark. It becomes hard for such a heart to accept the good things (of apt way). It can’t judge between good & bad.”
Imam Ibn-e-Jarir رحمت اللّہ said:
“When a Believer commits a sin, a black dot is drawn on his heart. If he gives up & regrets over it, than that black dot vanishes & heart becomes pious again. But if he does not stop from commiting sins, his heart becomes dark.
Thus excess in sins puts a veil on the heart which ultimately fails to accept the truth & thus attaining the wrong path.
May Allah عزوجل guide us to refrain from sins & help us to do good.
Any mistake, on my part, if found may please be forgiven.