AboveTheThrone.Com | Al-Dhahabi in al-Siyar: The Statement of al-Muzanee (d. 264H) - The Tawhid of Any Person is Not Valid Until He Knows Allaah Is Above His Throne

Imam al-Dhahabi reports in al-Siyar (12/494):

قال عمرو بن تميم المكي سمعت محمد بن إسماعيل الترمذئ قال سمعت المزني يقول لا يصح لأحد توحيد حتى يعلم أن الله تعالى على العرش بصفاته قلت له مثل أي شيء قال سميع بصيرعليم

'Amr bin Tamim al-Makki said: I heard Muhammad bin Isma'il al-Tirmidhi [who] said: I heard al-Muzanee saying, "The Tawhid of any [person] is not valid, sound until he knows that Allaah the Exalted is over His Throne, with His attributes." I said to him, "Like what?" He said, "Hearing, seeing, knowing."

Refer also to the statement of al-Muzanee as found in his book Sharh al-Sunnah (see here) where he affirms Allaah is above the Throne, bi dhatihi (with His essence).