The Excellence of Supplicating in one’s Absence

Imam Al-Nawawi’s Riyad-us-Saliheen
Chapter 251
The Excellence of Supplicating in one’s Absence

Allah, the Exalted, says:

And those who came after them say: `Our Rubb! Forgive us and our brethren who have preceded us in Faith.”’ (59:10)

And ask forgiveness for your sin, and also for (the sin of) believing men and believing women”. (47:19)

Our Rubb! Forgive me and my parents, and (all) the believers on the Day when the reckoning will be established.” (14: 41)

1494. Abud-Darda’ (May Allah be pleased with him) reported: I heard the Messenger of Allah (sallallaahu ’alayhi wa sallam) saying, “Whenever a Muslim supplicates for his (Muslim) brother in his absence, the angels say: `May the same be for you too‘.”
[Muslim].

1495. Abud-Darda’ (May Allah be pleased with him) reported: The Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “The supplication of a Muslim for his (Muslim) brother in his absence will certainly be answered. Everytime he makes a supplication for good for his brother, the angel appointed for this particular task says: `A   meen! May it be for you, too‘.”
[Muslim].