He denies that Allah rose above His Throne and he is asking: where was Allah before He created the heavens and before He created the Throne?

Firstly: 

In the answer to question no. 992, we quoted the evidence that proves that Allah, may He be exalted, is above His creation and that He, may He be glorified, is above the heavens. 

In the answer to question no. 146779 we explained that the Throne of the Most Gracious, may He be exalted, was above the water before He created the heavens and the earth and all that is in them. 

Secondly: 

Before the creation of the Throne, and before the creation of the heavens and the earth, and before the creation of directions, there was Allah, may He be exalted, and there was nothing before Him, nothing after Him, and nothing besides Him, as al-Bukhaari (7418) narrated that ‘Imraan ibn Husayn (may Allah be pleased with him) said: I was with the Prophet (blessings and peace of Allah be upon him) when some people from Banu Tameem came to him and he said: “O Banu Tameem, accept the good news.” They said: You have given us the good news; now give us something. Then some people from Yemen came in and he said: “Accept the good news, O people of Yemen, for Banu Tameem did not accept it.” They said: We accept it, for we have come to you to learn about the religion and to ask you how the matter was from the very beginning. He said: “There was Allah and nothing existed before Him, and His Throne was on the water. Then He created the heavens and the earth, and He wrote all things in al-Lawh al-Mahfooz.” 

Al-Haafiz (may Allah have mercy on him) said: 

This indicates that there was nothing besides Him: neither water nor the Throne nor anything else, because these are things other than Allah, may He be exalted. End quote. 

One of the supplications of the Prophet (blessings and peace of Allah be upon him) was that which was narrated by Muslim (2713): “Allaahumma anta al-awwal fa laysa qablaka shay’un, wa anta al-aakhir fa laysa ba’daka shay’un, wa anta al-zaahir fa laysa fawqaka shay’un wa anta al-baatin fa laysa doonaka shay’un (O Allah, You are the First so there is nothing before You, and You are the Last so there is nothing after You. You are al-Zaahir [the greatest and highest] so there is nothing above You, and You are al-Baatin [aware of the subtlest secrets] so there is nothing closer than You).” 

It was narrated that Abu Razeen said: O Messenger of Allah, where was our Lord before He created His creation? He said: “Nothing existed but Him, with nothing beneath Him and nothing above Him. Then He created His Throne above the water.”

Narrated by at-Tirmidhi (3109), Ibn Maajah (182) and Ahmad (15755). 

This hadith was classed as saheeh by at-Tabari; as hasan by at-Tirmidhi, adh-Dhahabi and Ibn Taymiyah; and as da‘eef by al-Albaani in Da‘eef at-Tirmidhi.

To sum up: Allah, may He be glorified and exalted, is unique in His divinity, so there was no created entity with Him in past eternity. Rather He was Allah, and there was nothing before Him. Then He created His creation and rose above His Throne, as He has told us in His Book, in such a manner as He willed, may He be exalted, and there is none that can dispute with Him regarding His sovereignty and He has no partner in His authority. 

Secondly: 

This question that the deniers pose to those who affirm that Allah, may He be exalted, is above His creation and rose above His Throne should, rather, be addressed to them, if they suggest that that Allah, may He be exalted, needs His Throne or His heavens or anything of His creation. Exalted be Allah far above what they say. But if those who affirm the divine attributes affirm, in addition to that, what every Muslim believes, that Allah, may He be exalted, is completely independent of means and has no need of any of His creation, and no one opposes Him in His sovereignty and His authority, and that the Throne, the heavens and all creatures only exist and continue to exist by the support of their Lord, Who is the one who created them and created them for the purpose for which they were created, and sustained them and provided for them, and that the Throne needs its Lord, and it is held up by His might and power, for “Verily! Allah grasps the heavens and the earth lest they move away from their places, and if they were to move away from their places, there is not one that could grasp them after Him. Truly, He is Ever Most Forbearing, OftForgiving” [Faatir 35:41] – if that is the case (that everything needs Allah and He has no need of anything), there is no point to this argument. 

Moreover, this question could be asked of the deniers too, and this assumption cannot be avoided unless they affirm that which is proven by Islamic texts and common sense, that Allah is above His creation. 

Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: 

Allah was and there was nothing with Him, then He created the universe, so it must be one of three scenarios: 

Either He created it within Himself, then He separated from it. This is impossible; Allah is far above being in contact with filth and other things; 

Or He created it outside Himself, then He entered it. This is also impossible; Allah is far above entering into His creation. There is no dispute among any of the Muslims that these two scenarios are impossible. 

Or He created it outside of Himself, and did not enter into it. This is the truth; no other scenario is possible and nothing but this is befitting to Allah.

End quote from Majmoo‘ al-Fataawa (5/152) 

As that is the case, it may be said: what is the reservation that may result from affirming what Allah affirmed about Himself, that He is above His creation and He rose over His Throne, which does not lead to any similar or worse reservation in the case of those who deny that? 

Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) also said:

It is known that there is nothing in the text that mentions the word direction or denies it, as it mentions and affirms His being high, rising above, being above, ascending to Him, and so on. So it may be said to the one who denies the idea of direction: Do you mean by direction something that exists and is created? For Allah is not encompassed by His creation. Or do you mean by direction what is beyond the universe? For undoubtedly Allah is above the universe and distinct from His creation. Similarly, it could be said to the one who says that Allah is in a particular direction: Do you mean thereby that Allah is above the universe? Or do you mean that Allah is encompassed by any of His creation? If you mean the former, that is true, but if you mean the latter, that is false. 

Allah is as the imams (leading scholars) of Ahl as-Sunnah said, above His heavens, over His Throne, distinct from His creation. End quote from Majmoo‘ al-Fataawa (3/41-42) 

And Allah knows best.