Is the declaration of Zihar (unlawful declaration of divorce equivalent) valid for one whose divorce is invalid?

Primary text

The declaration of Zihar is invalid for anyone whose divorce is invalid. This includes a child, a person whose mind has been removed due to insanity, fainting (ighma'), or sleep. This view is held universally without known dispute and is affirmed by Al-Shafi'i, Abu Thawr, and the Ashab Al-Ra'y (Hanafi scholars). No specific textual evidence (Quran or Hadith) is cited for this consensus, as it rests on the principle that the validity of Zihar follows the validity of divorce.