Whosoever seeks forgiveness for the believing men and the believing women, Allaah will record for that person – equivalent to every believing man and believing woman – a good deed.

 
[Related by al-Haythamî in Majma’az-Zuwaa‘id (l/210) where he said: “The isnaad is jayyid.” , Tabaraanee (2155) and graded as “Hasan” (good) by Shaikh al-Albaanee in Saheeh al-Jami` (6026)]