Ibn ‘Umar reported God’s messenger as saying, “God accepts a servant’s repentance till he gives up his spirit in death.”*
*The Arabic is ma lam yugharghir, which might, be translated literally "as long as he has not died with the death rattle in his throat."
Abu Huraira reported God’s messenger as saying, “When a believer sins there is black spot in his heart, and if he repents and asks pardon his heart is polished; but if he does more it increases till it gains the ascendancy over his heart. That is the rust mentioned by God most high, 'Nay, but what they were committing has spread like rust over their hearts'.” 1
1. Qur’an, lxxxiii, 14.
Ahmad, Tirmidhi and Ibn Majah transmitted it, Tirmidhi saying this is a hasan sahih tradition.
Abu Sa'id reported God’s messenger as saying that the devil said, “By Thy might, my Lord, I shall continue to lead Thy servants astray as long as their spirits are in their bodies” The Lord who is great and glorious replied, “By my might, glory and exalted station, I shall con tinue to pardon them as long as they ask my forgiveness.”