What is the ruling on waqfs (endowments) for bid'ah (innovations in religion)? And what is the ruling on waqfs for reciting the Qur’an for the deceased? And what is the ruling on purchasing an invalid waqf?

Every endowment for an innovation (bid'ah) or a sin is void, and this is considered correct. This is agreed upon among Muslims, and there is no dispute among scholars regarding it. So, whoever vows to obey Allah, let him obey Him; and whoever vows to disobey Allah, let him not disobey Him. Money should not be spent except for a benefit in religion or in worldly matters.

The remaining disagreement is on how to void an endowment for an innovation or a sin: whether by returning the money to the heirs or by dedicating the endowment to a legitimate charitable cause. If the judiciary rules to return the endowment to the heirs, there is no harm in that.

As for an endowment for someone to recite the Quran and dedicate the reward of its recitation to the endower, it is illegitimate and does not benefit the deceased. Giving a wage for reciting the Quran for the deceased is an innovation (bid'ah) that has not been transmitted from any of the predecessors (Salaf). Rather, it is more correct to spend this type of endowment on its legitimate kind of good deeds, such as charitable Quran memorization schools, because that is closer to the endower's intention and of its kind.