Is forgiveness granted to the one who says, "O Allah, forgive the Muslim men and women, and the believing men and women, those who are alive among them and those who are dead," in the number of the Muslim and believing men and women, both living and dead?

It is permissible to make this supplication and others for Muslim men and women, but specifying a certain reward based on the number of those forgiven has no basis. It has been reported that whoever seeks forgiveness for believing men and believing women, Allah will record a good deed for him for every believing man and believing woman. It has also been reported that a Muslim's supplication for his brother in his absence is answered, and the angel says: Amen, and to you the same.