What is the difference between Sadaqah (charity) and Sadaqah Jariyah (ongoing charity), what are examples of each, and does the reward for Sadaqah Jariyah remain until the Day of Judgment—such as for someone who built a mosque that was later demolished?

Perpetual charity is an endowment (waqf). Its definition is: to tie up the principal and donate its usufruct. It has been reported that Umar (may Allah be pleased with him) tied up land in Khaybar and gave it as charity.

Perpetual charity can be in the form of building a mosque, buying copies of the Qur’an, endowing a house or a shop whose proceeds are spent on the needy, or contributing to the building of a charitable hospital.

As for non-perpetual charity, its principal is not tied up; rather, it is given to the poor to own and benefit from, such as giving money, food, or clothing.

If an endowment becomes ruined and no longer beneficial, it is permissible to sell it and use its price for another endowment. If a part of it is still usable, it is permissible to sell the ruined part to repair the remaining one.

The reward for an endowment continues for its donor as long as the endowment remains, or even if it is sold and placed in another endowment. And whoever builds a mosque, even a small one, Allah will build for him a house in Paradise.