The Location of Paradise

Question :

If the width of Paradise is as the width of thheavensand the earth, then where it is in this creation, which isfilled by the heavens and the earth?

Answer:

Before answering this question, we must preface it bysaying whatever is in the Book of Allah and whatever hasbeen authentically reported from the Messenger of Alläh isthe truth and it is not possible that it contradicts the existentreality, for the existent tangible realitytrue and it isimpossible to doubt it. What is confirmed by the Qur'an andSunnah is (also) the truth, which is not possible to doubt, noris it possible for two truths to contradict each other in a waywhich makes it impossible to reconcile them both. It isconfirmed by the Qur'an that the breadth of Paradise is as thebreadth of the heaven and the earth; and in another Verse:
"as wide as are the heavens andearth".

This is the truth, without doubt. A Jew asked the Prophetabout this Verse saying: "If the width of Paradise is that of theheavens and the earth, then where is the Fire?" The Prophet ﷺ replied:
"When the night comes, where is the day?"

Also, the statement of the questioner that this creationcontains naught but the heavens and the earth is incorrect. Inthis creation are the heavens and the earth, the Kursi and the 'Arsh.The Prophet used to say, after he straightened up from bowing in prayer:
«Filling the heavens, filling the earth and filling whatever elseYou wish."

There is a world other than the heavens and the earth, knownto none but Allah. Likewise, we know from Him what He, theMost Glorified, Most High hasaught us, such as the 'Arshand the Kursi; and the 'Arsh is the highest of all created things.And Alläh, the Most Glorified, Most High ascended over the'Arsh in a manner befitting His Majesty and His Greatness.

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 1 Pages 181-182