Is it permissible for an ongoing charity (sadaqah jariyah), such as building a mosque, to be dedicated on behalf of all deceased Muslims, or must the deceased person be specified by name?

It is permissible for a person to give charity or donate the reward of charity to relatives and strangers alike. It is also permissible to dedicate the reward of charity to all deceased Muslims. Ibn al-Qayyim said: "The souls of the dead benefit from the efforts of the living in two matters upon which the Sunnis are in agreement: First, what the deceased initiated during their lifetime, and second, the supplication of Muslims for them, their seeking forgiveness for them, giving charity, and performing Hajj." Some scholars believe that it is better for the one giving charity to intend their charity for themselves and for all believing men and women, because it reaches them, and nothing is diminished from their reward.