What is the ruling on giving charity to a poor person whose lineage to the Household of the Messenger of Allah (peace be upon him) has been established, and who is not given the khums?

Charity (sadaqah) is not permissible for theal al-Bayt (family) of the Messenger of Allah, peace and blessings be upon him, whether or not they have received their share of the khums (one-fifth). This applies specifically to obligatory charity, such as zakat. As for voluntary charity (sadaqat at-tatawwu'), it is permissible for them according to the well-known view of the Shafi'i and Hanbali schools, because it is a supererogatory act and not from the "filth of people," and it is treated like a gift (hibah), which is permissible for the family of the Prophet, peace and blessings be upon him.