What is the ruling regarding a wife insulting her husband and calling him an infidel, and abusing his mother, despite her knowing and memorizing the Qur'an?

You erred in preferring your mother over Sayyida Khadijah. However, your wife's accusation of disbelief against you is a grave sin and clear injustice. We advise you to reconcile with your wife through admonition, forsaking her in bed, and a non-injurious beating for discipline, which is a beating that does not break a bone or disfigure a limb.