"There is no doubt that the heart becomes covered with rust , just as metal dishes- silver, and their like - become rusty. So the rust of the heart is polished with dhikr (remembrance of Allah) for dhikr polishes the heart until it becomes like a shini mirror. However , when dhikr is abandoned , the rust returns ; and when it commences then the heart again begins to be cleansed. Thus the heart becoming rusty is due to two matters; sins and ghaflah (neglecting remembrance of Allah). Likewise , it is cleansed and polished by two things : Istigfar (seeking Allah's forgiveness) and dhikr."
