After performing Asr prayer seek forgiveness from Allah seventy-seven times (77)
Muhammad Ibn Fuzail Sairafee on the authority of Imam Reza (a.s.) who on the authority of his forefathers (a.s.) who on the authority of the Holy Prophet (s.a.w.a.) mentions this that he (s.a.w.a.) said to a person Allah will settle down your sins committed during seventy-seven (77) years. by this recitation.”
The person exclaimed: ‘If I do not get an age of seventy-seven years?’,Holy Prophet (s.a.w.a.) replied:“Then the sins committed by your father would be forgiven.”
The person again asked: ‘If I and my father do not get an age of seventy-seven years?’.Holy Prophet (s.a.w.a.) answered:“Then the sins committed by you, your father or your mother would be forgiven.”
The person again retorted: ‘If I, my father and my mother do not get an age of seventy-seven years?’, Holy Prophet (s.a.w.a.) responded:“Then the sins committed by you, your father, your mother and your relatives would be forgiven.”

[2]Jaame’ Ahaadis al-Shiah, vol. 6, p. 104; Wasaael al-Shiah, vol. 4, p. 1053<