Is it permissible to establish an ongoing charity (sadaqah jariyah) by dedicating books of knowledge for a financially able student, or is it exclusively for those who are unable to afford them?

Ongoing charity is the endowment (waqf), which is the dedication of an asset and the channeling of its usufruct. The endower (waqif) designates the beneficiaries of the endowment. If a specific category is stipulated, adherence to that condition is obligatory; otherwise, both the poor and the rich are equally entitled to benefit from it, as an endowment does not require its beneficiaries to be exclusively the poor.