Safwan ibn Abdullah, the son-in-law of Abu Darda (r.a.) said:
One day I went to the house of my father-in-law. My mother-in-law, Ummu Darda (r.anha) was there but Abu Darda was not at home. She asked me:
“Are you going to go Hajj this year?” I replied:
“Yes.”
“Make Dua to Allahu Ta’ala for us. Indeed I heard Rasulullah (s.a.w.) say:
“A person who makes Dua in secret for their Muslim brother, their Dua would be accepted. An angel will stand besides this person and when they make the Dua will say: “Amin, may Allahu Ta’ala bless you with want you wanted for your Muslim brother.”
I left her presence and I met Abu Darda on the way in the market. He narrated to me the same Hadith from Rasulullah (s.a.w.)
(Muslim)
Rasulullah (s.a.w.) said:
“There are two Dua’s that when said, no curtains remains between them and Allah: the Dua of the oppressed and the Dua said in secret for a Muslim brother.” (Tabarani)
“Dua said in secret is equal to seventy Duas said in the open.”
“There are five Duas which will never be rejected: The Dua of a pilgrim until they return, the Dua of a warrior until they return, the Dua of the oppressed until they have what they deserve, the Dua of an ill person until they are cured, the Dua of a person for their Muslim brother said in secret without them knowing.
The Dua which will be accepted the fastest, is the Dua of a Muslim for their fellow Muslim.” (Sunan Kubra, Bayhaqi)
“A person who makes a Dua for themselves that is rejected, will not be rejected when said for their fellow Muslim.” (Ihya Ulumiddin)
Abu Darda (r.a.) said:
“Indeed I make Dua for seventy of my Muslim brothers saying each one of their names while in Sajdah.” (Ihya Ulumiddin)
