What is the ruling on swearing by the Qur'an, that is, by placing one's hand upon it?

Swearing an oath by placing one's hand on the Mus'haf (Quran) has not been reported from the Prophet (peace be upon him) nor from his Companions. It is one of the innovations that judges introduced to emphasize the gravity of an oath and deter wrongdoers. The Shafi'is have permitted it. If a person swears a false oath, it is a "Yamin Ghamus" (a perjurious oath that plunges one into sin), which entails many transgressions, and there is disagreement regarding its expiation.