Is it permissible for a wife who is harmed by her husband to record or film his repeated insults and her expulsion from the home, or to copy his electronic conversations that prove his confession, in order to present this as evidence before the judge?

A husband's insult and expulsion of his wife contradict the Shari'ah's command for good companionship. There should be understanding between the spouses and a keenness to resolve their problems wisely. If the marital bond cannot be maintained, then separation should be with kindness.

If the husband engages in abusive behavior, and the wife has no way to prove it except by recording his speech, photographing his actions, and copying his electronic conversations, then there is no blame upon her for doing so, especially since she is fending off harm from herself thereby. Some jurists have permitted the testimony of someone who conceals themselves for a necessity, and they do not consider it spying. What is permitted out of necessity is to be estimated by its measure.