Is a woman permitted to leave her marital home and return to it without restriction, merely upon apologizing, if she has been severely harmed by her husband, such as through verbal abuse or brutal beating? And is her departure in this case considered an act of defiance (nushuz)?

A husband must refrain from harming his wife and treat her kindly, as Allah Almighty says: (Then [after divorce] either retain her with kindness or release her with goodness). If he fears his wife's defiance (nushooz), he should treat her gently, starting with admonition, then abandoning her in bed, then a non-severe beating, provided he believes it will be beneficial. If the husband causes harm and then apologizes and guarantees it will not recur, the wife should accept his apology and forgive him. If the harm infringes upon her dignity and honor according to custom, then she has the right to leave the house, and this is not considered defiance (nushooz).