It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, who said: The ranks of the deceased are elevated even after his death. So he asks: O my Lord! Which deed is it because of which my ranks have been elevated? It is said: Your son has sought forgiveness for you.
Hadith Referenceصحيح الادب المفرد / 27
Hadith Takhrij(حسن الإسناد)
Hadith 28
28/37 (صحيح الإسناد) عن محمد بن سيرين قال: كُنَّا عِنْدَ أَبِي هُرَيْرَةَ لَيْلَةً، فَقَالَ: "اللَّهُمَّ اغْفِرْ لِأَبِي هُرَيْرَةَ، وَلِأُمِّي، وَلِمَنِ اسْتَغْفَرَ لَهُمَا" قَالَ لِي مُحَمَّدٌ: فَنَحْنُ نَسْتَغْفِرُ لَهُمَا؛ حَتَّى نَدْخُلَ فِي دَعْوَةِ أَبِي هريرة.
It is narrated from Muhammad bin Sirin that he said: One night we were with Sayyiduna Abu Hurairah (may Allah be pleased with him), so he said: «اللَّهُمَّاغْفِرْلأَبِيهُرَيْرَةَ ، وَلِأُمِّي ، وَلِمَنِاسْتَغْفَرَلَهُمَا» "O Allah! Forgive me and my mother, and forgive all those who seek forgiveness for both of us." Muhammad said to me: We will continue to seek forgiveness for both of them so that we may be included in the supplication of Sayyiduna Abu Hurairah (may Allah be pleased with him).
It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: "When a person dies, his deeds come to an end except for three: ongoing charity, knowledge from which benefit is derived, or a righteous child who prays for him."
It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them) that a man said: O Messenger of Allah! My mother has passed away and she did not make any will. If I give charity on her behalf, will it benefit her? The Prophet (peace and blessings of Allah be upon him) said: "Yes."