All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Our answer is summarized in the following points:
Firstly, Shaykh Al-Islam Ibn Taymiyyah authored a book entitled Ar-Risaalah Al-ʻArshiyyah, commonly known as Kitaab Al-ʻArsh. Al-Aloosi said about this book, "It is an unmatched book on this topic."
Secondly, we have previously issued a fatwa in the Arabic section about Imaam Abu Hayyaan and the extent of his adherence to the Salafi methodology in creed. Since the questioner occasionally sends some of his questions in Arabic, we believe that he has a good command of Arabic, so we ask him to refer to that fatwa in the Arabic section; it is No. 114653. Its content makes us in no need of repeating it here.
Thirdly, it was said that the disagreement between Abu Hayyaan Al-Andalusi with Shaykh Al-Islam Ibn Taymiyyah was because the latter stated that Seebawayh committed mistakes regarding some grammar issues. Accordingly, a disagreement erupted between them. Initially, Abu Hayyaan used to praise Ibn Taymiyyah, but after that incident, he began to criticize him. The story was mentioned by Ibn Hajar in Ad-Durar Al-Kaaminah.
Fourthly, the statement that Abu Hayyaan attributed to Ibn Taymiyyah, that "Allah sits on the Throne but has left a place of it unoccupied, in which to seat the Messenger of Allah, sallallahu ‘alayhi wa sallam" does not exist in Ar-Risaalah Al-ʻArshiyyah or in any of Ibn Taymiyyah's books. The scholars said that this was not quoted from him.
Al-Aloosi, refuting An-Nabhaani, said:
"The books of Shaykh Al-Islam (Ibn Taymiyyah) in every discipline are available, praise be to Allah. So in which book did he say that Allah sits on the Throne and that He has left a place for the Messenger of Allah, sallallaahu ‘alayhi wa sallam, to sit with Him? In which book did Abu Hayyaan see this statement? The authenticity of such a quote must be verified according to the rules of debate. After verification, we can discuss it. How could such a statement be authentically attributed to Ibn Taymiyyah when his books explicitly stated otherwise, as evident to anyone who follows his books and statements."
Fifthly, please refer to fatwas 295258 and 307534.
Allah knows best.