Is it permissible to perform an ongoing charity (sadaqah jariyah) on behalf of a deceased mother, and what are its examples and types? Does contributing to the building of a mosque or purchasing items that benefit the poor count as an ongoing charity?

Giving Sadaqah on behalf of the deceased and supplicating for them are among the acts whose reward reaches them, without any disagreement. This should be done, as ongoing charity (Sadaqah Jariyah) was mentioned in the Hadith: "When a person dies, all his deeds come to an end except for three: ongoing charity, beneficial knowledge, or a righteous child who supplicates for him." Ongoing charity is an endowment (Waqf), which is holding the principal and dedicating its usufruct. Participating in building a mosque falls under ongoing charity. However, buying things for a poor person, such as a blanket or food, is a charity from which the deceased benefits and its reward reaches them, but it is not an ongoing charity.