Imam Dhun-Nun Al-Misri said:
وسئل ذو النون المصري رضي الله عنه عن قوله تعالى الرحمن على العرش استوى
فقال: أثبت ذاته ونفى مكانه، فهو موجود بذاته، والأشياء بحكمته كما شاء
Dhul Nun al-Misri was asked about the saying of Allah: “ar-Rahmanu `alal `arsh istawa” He answered: “He affirmed His existence, and denied that He has a place. So He Himself exists independently, while other things exist by His Wisdom as He Wills.”
Source: Risalah Al-Qushayriyyah,