ALLAH 
SAYS: “And those who came after them say ‘Lord, forgive us and our brethren who came to faith before us.’” [1].
SAYS: “And those who came after them say ‘Lord, forgive us and our brethren who came to faith before us.’” [1].
Allah says: “And seek forgiveness for your sins, and for the men and women who believe.” [2].
says: “And seek forgiveness for your sins, and for the men and women who believe.” [2].
Allah says that Ibrāhīm 
prayed: “Lord, forgive me, my parents, and [all] believers on the Day the Reckoning takes place.” [3].
says that Ibrāhīm prayed: “Lord, forgive me, my parents, and [all] believers on the Day the Reckoning takes place.” [3].
Allah says that Nūḥ e said: “Lord, forgive me, my parents, whoever enters my house in faith, and [all] believing men and believing women.” [4].
says that Nūḥ e said: “Lord, forgive me, my parents, whoever enters my house in faith, and [all] believing men and believing women.” [4].
We relate in the Ṣaḥīḥ of Muslim that Abū ad-Dardā’ 
reported that he heard the Messenger of Allah 
say: “No Muslim slave [of Allah] makes du‘ā’ for his brother in his absence without an angel saying: ‘And the same for you.’” According to another report in Muslim, Abū ad-Dardā’ related that Allah’s Messenger used to say: “The du‘ā’ of a Muslim man for his brother in his absence is answered; at his head there is an angel who has been [specially] appointed. Every time he makes du‘ā’ for his brother’s welfare, the appointed angel says: ‘Āmīn, and the same for you.’” [5].
reported that he heard the Messenger of Allah say: “No Muslim slave [of Allah] makes du‘ā’ for his brother in his absence without an angel saying: ‘And the same for you.’” According to another report in Muslim, Abū ad-Dardā’ related that Allah’s Messenger used to say: “The du‘ā’ of a Muslim man for his brother in his absence is answered; at his head there is an angel who has been [specially] appointed. Every time he makes du‘ā’ for his brother’s welfare, the appointed angel says: ‘Āmīn, and the same for you.’” [5].We relate in the books of Abū Dāwūd and at-Tirmidhī that Ibn ‘Umar 
narrated that the Messenger of Allah said, “The du‘ā’ that is answered most rapidly is the du‘ā’ of one absent person for another who is absent.” [6].According to at-Tirmidhī [this hadith] is weak.
narrated that the Messenger of Allah said, “The du‘ā’ that is answered most rapidly is the du‘ā’ of one absent person for another who is absent.” [6].According to at-Tirmidhī [this hadith] is weak.References
[1] Qur’ān 59:10.
[2] Qur’ān 47:19.
[3] Qur’ān 14:41.
[4] Qur’ān 71:28.
[5] Muslim (2732, 2733) and Abū Dāwūd (1534).
[6] Abū Dāwūd (1535) and at-Tirmidhī (1981), with a slight variation in the wording.