by Imam Muslim, translation by Abdul Hamid Siddiqui , Volume: The Book of Faith (Kitab Al-Iman)
Chapter: PROOF IN SUPPORT OF THE FACT THAT HE WHO DIED IN UNBELIEF HIS DEED WOULD NOT BE OF ANY AVAIL TO HIM
'A'isha reported: I said: Messenger of Allah, the son of Jud'an established ties of relationship, fed the poor. Would that be of any avail to him? He said: It would be of no avail to him as he did not ever say: O my Lord, pardon my sins on the Day of Resurrection.