It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: "The supplication that is accepted the quickest is the supplication made by a person for another in his absence."
Hadith Referenceالادب المفرد / كتاب / 623
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«ضعيف : أخرجه أبوداؤد ، كتاب الوتر ، باب الدعاء بظهر الغيب : 1535 و الترمذي : 1980 - انظر المشكاة : 2247»
It is narrated from Sayyiduna Abu Bakr Siddiq (may Allah be pleased with him) that the supplication of a religious brother for his religious brother is accepted.
Hadith Referenceالادب المفرد / كتاب / 624
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه ابن وهب فى الجامع : 161 و الدولابي فى الكني : 959/3 و البيهقي فى الشعب : 8640»
Narrated from Sayyiduna Safwan bin Abdullah bin Safwan (may Allah be pleased with him), and in his marriage was Darda, the daughter of Sayyiduna Abu Darda (may Allah be pleased with him). He says: I came to them in Syria, and in the house was Sayyida Umm Darda (may Allah be pleased with her), while Sayyiduna Abu Darda (may Allah be pleased with him) was not present there. Sayyida Umm Darda (may Allah be pleased with her) said: Are you going for Hajj this year? I replied: Yes! She said: Then pray for good for us as well, because the Prophet (peace and blessings of Allah be upon him) used to say: “Indeed, the supplication of a Muslim for his brother in his absence is surely accepted. When he supplicates, an angel is appointed at his head. Whenever he prays for good for his brother, the angel says: Ameen, and for you the same.” He says: Then I met Sayyiduna Abu Darda (may Allah be pleased with him) in the market, and he said the same thing and narrated this hadith from the Prophet (peace and blessings of Allah be upon him).
Hadith Referenceالادب المفرد / كتاب / 625
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه مسلم ، كتاب الذكر و الدعاء : 88 ، 2733 و ابن ماجه : 2895 - انظر الصحيحة : 1399»
It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that a man made a supplication: "O Allah, forgive only me and Muhammad (peace be upon him)." The Prophet (peace be upon him) said: "You have withheld your supplication from many people."
Hadith Referenceالادب المفرد / كتاب / 626
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه أحمد : 6849 و ابن حبان : 986 - الإرواء : 171 - البخاري ، كتاب الأدب ، باب رحمة الناس و البهائم ، عن أبى هريره : 6010»
It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that I heard the Prophet (peace and blessings of Allah be upon him) seeking forgiveness in one gathering a hundred times in this way: "O Lord! Forgive me, accept my repentance, and have mercy on me. Indeed, You are the Acceptor of repentance, the Most Merciful."