[Seven]: Then Allaah, the Most High, said:
وَسِعَ كُرْسِيُّهُ السَّمَاوَاتِ وَالْأَرْضَ ۖ وَلَا يَئُودُهُ حِفْظُهُمَا ۚ وَهُوَ الْعَلِيُّ الْعَظِيمُ
His kursi extends over the heavens and the earth encompassing them all, He feels no fatigue in guarding and preserving them. And He is the Most High, the Most Great.
The kursi [literally: footstool] is mawdi’ul qadamayn (place of the Feet) of Allaah, Most Mighty and Most Majestic, and it is before the ‘arsh like a front to it. This was authentically related by ibn ‘Abbaas (رضي االله عنهما) in a mawqoof  type of narration. This is agreed upon by the majority of ahlussunnah wal jamaa’ah. In fact, this is asserted by Shaykh-ulIslam Ibn Taymeeyah, [Imaam] Ibnul Qayyim, and others from the people of knowledge and from the verifying scholars.
Some have said that al-kursi is the ‘arsh itself. However, this is not true because the ‘arsh is greater, more spacious, and more profound in its extent of encompassing than al-kursi. It has also been narrated on the authority of ibn ‘Abbaas (رضي االله عنهما) that al-kursi represents Allaah’s Knowledge. But I do not think that this narration is authentic because this meaning (i.e. knowledge) is not the true meaning for the word al-kursi in the classical Arabic language nor in the common (‘urfi) language. In fact, it is very unlikely that this transmission from ibn ‘Abbaas (رضي االله عنهما) is an authentic one . Hence, al-kursi is mawdi’ul qadamayan.
The greatness of al-kursi is clearly stated in the hadeeth in which the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) said:
“The seven heavens and the seven earths by the side of al-kursi are naught but as a ring thrown down in a desert land, and such is al-kursi with respect to al-’Arsh (the Throne).” 
This hadeeth indicates the vastness of these immense creations and which are, with respect to us, from the world of al-ghayb. That is why Allaah سبحانه و تعالى says:
أَفَلَمْ يَنظُرُوا إِلَى السَّمَاءِ فَوْقَهُمْ كَيْفَ بَنَيْنَاهَا وَزَيَّنَّاهَا وَمَا لَهَا مِن فُرُوجٍ
Have they not looked at the heavens above them, how We have made it and adorned it, and there are no rifts in it. [Qur’aan, Soorat Qaaf (50:6)].
He سبحانه و تعالى did not say: “Have they not looked at al-kursi (or al- ‘arsh)…,” because this is something that is not seen by us.
Had it not been that Allaah had informed us about it (al-kursi or al-‘arsh), we would not have known of it.
Allaah’s saying: “His kursi extends over and encompasses the heavens and the earth”, supports the opinion held by Shaykh-ul-Islam Ibn Taymeeyah and by other verifying scholars that the heavens and the earths all have a spherical shape, because this is a matter acknowledged by sensory perception, and through information, though the latter method may have been hidden from many of the preceding people. The proof for this from the Qur’aan is in the saying of Allaah, the Most High:
إِذَا السَّمَاءُ انشَقَّتْ
وَأَذِنَتْ لِرَبِّهَا وَحُقَّتْ
وَإِذَا الْأَرْضُ مُدَّتْ
When the heaven is split asunder [on the Day of Resurrection], and listens and obeys its Rabb,—and it must do so; And when the earth is stretched forth…[Qur’aan, Soorat Al-Inshiqaaq (84:1-3)].
Allaah’s saying: “And when the earth is stretched forth,” necessitates that it is now unstretched. In addition, the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) said that on the Day of Resurrection, the earth will be stretched forth like stretched leather, the example of which is drawn for emphasis. 
Another proof is the saying of Allaah, the Most High:
يُكَوِّرُ اللَّيْلَ عَلَى النَّهَارِ وَيُكَوِّرُ النَّهَارَ عَلَى اللَّيْلِ
Yukawwiru the night around the day [making it to be a covering upon the day] and Yukawwiru the day around the night. [Qur’aan, Soorat Az-Zumar (39:5)].
Yukawiru means: “to wind round,” like in our saying, “the akwaar (singl. kawr) of the turban,” meaning the turns of the turban upon the head.
We know that the day and night succeed each other upon earth and in doing so, this entails that the earth is spherical, because a thing would not be wound around in a round form except upon something ball-shaped. Nowadays, it is witnessed that the earth is spherical in form.
The fact that al-kursi extends over and encompasses the heavens and the earth is evidence that it is wound round in a round form.
Regarding al-‘arsh, it has been reported that the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) described it as being like a dome above the heavens. The dome-shape being round but neither fully spherical nor flat, and its middle is high like that of a tent. 
Then, Allaah, the Most High, said:
وَلَا يَئُودُهُ حِفْظُهُمَا
And He [Allaah سبحانه و تعالى] feels no fatigue in guarding and preserving them [i.e. the heavens and the earths].
This attribute of Allaah [feeling no fatigue] is an Attribute of negation. So, what are the Attributes required for guarding and preserving [the heavens and the earths] such that we know that this negation [of fatigue] is in fact an affirmation of their perfection? It is essential that the guarding and preserving require Life, Knowledge, Ability, Might, Mercy, and possibly other attributes. What is important is that the negation implies the perfection of Allaah’s Knowledge, Ability, Might, and Mercy as well as the other related Attributes that are entailed by His (سبحانه و تعالى) preserving and guarding.
 Mawqoof: lit. “stopped”. It is a narration from a companion only. The hadeeth attributed to the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) is called marfoo’. Shaykh Ibn ‘Uthaymeen (rahimahullaah) commented, “Had it not been that Ibn ‘Abbaas (رضي االله عنهما) is one whom it is said that he takes from the Israelite transmissions (israa’eeliyyaat: narrations from the traditions of the People of the Book), we would have said that this transmission (regarding al-kursi) takes the form of marfoo’ tradition, because it deals with knowledge of al-ghayb (the world of unperceived realities). When it comes to this kind of knowledge, there is no room for ijtihaad (scholarly deductions). When a sahaabi (companion) says or does something which is not within the scope of ijtihaad, then it takes the marfoo’ type of tradition. The exception, however, is that if the narration from the sahaabi is of the form of akhbaar (news telling, relating information), then, if it is known that a sahaabi narrates from Bani Israa’eel, his transmission would not be marfoo’ because of the possibility that its source may be from Bani Israa’eel (an Israelite transmission). Knowing that the scholars are scrupulous in their inspection of what is attributed to the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم), they do not rule that a particular transmission is marfoo’ except when all of the possibilities that may hinder this ruling are ruled out.” Tafseer Aayat Al-Kursi, pp. 19-20.
Note: This report from Ibn ‘Abbaas is related by ‘Abdullaah Ibn al-Imaam Ahmad (As-Sunnah: 586), Ibn Abee Shaybah (al-‘Arsh: 61), Ibn Khuzaymah (At-Tawheed: 248), and by alHaakim (Al-Mustadrak: 2:282) who said it is saheeh according to the conditions of alBukhaari and Muslim. Imaam ath-Thahabi agreed to the authentication of al-Haakim. Ad-Daaraqutni reported it in his book As-Sifaat (36) as mawqoof from Ibn ‘Abbaas.
Shaykh al-Albaani said: “Its isnaad is saheeh, and its narrators are all reliable.” (Mukhtasar Al-’Uluw: 45).
 Shaykeh-ul-Islam Ibn Taymeeyah (Al-Fataawaa, 6:584), and Shaykh al-Albaani (AsSilsilah As-Saheehah, no. 109), stated the weakness of this narration from Ibn ‘Abbaas (رضي االله عنهما).
 Reported by Ibn Abee Shaybah (Al-‘Arsh, 58), and by Al-Baihaqi (Al-Asmaa’ wasSifaat, 862) with both narrations being from the way of Abee Thar (radhi Allaahu anhu). Shaykh al-Albaani (As-Silsilah As-Saheehah, no. 109) stated that there is no single authentic hadeeth attributed to the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) regarding al-kursi except this one.
 Reported by Ibn Jareer at-Tabari (Tafseer at-Tabari, 30:115-116) on the authority of ‘Ali Ibn al-Hussain. The transmission, however, is mursal.
Note: A hadeeth is categorized as mursal when the link between the taabi’ee (successor of the sahaabah) and the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) is missing.
 The infinitive noun is takweer, which means to round a thing in a round form.
 This has been reported in Sunan Abee Daawood (English Translation), no. 4708 and in the Sunnah by Ibn Abee ‘Aasim, no. 575, and by others. There is disagreement regarding the authenticity of its isnaad. Imaam ath-Thahabai and other scholars of hadeeth including al-Albaani graded its isnaad as weak. Imaam Ibn al-Aye supported its authenticity. The text describing al-‘Arsh as a dome over the heavens is supported by the context of an authentic narration reported by Imaam al-Bukhaari in his Saheeh (Arabic/English), vol. 9, no. 519 and in which the Prophet (صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم) said:
“There are one-hundred degrees in al-Jannah which Allaah has prepared for those who carry on jihaad in His Cause. The distance between every two degrees is like the distance between the sky and the earth, so if you ask Allaah for anything, ask Him for the Firdaws for it is the middle and highest part of al-Jannah and at its top is al-‘Arsh of ar-Rahmaan (Allaah), and from it gush forth the rivers of al-Jannah.”
The ‘Arsh being the roof of the Firdaws, which is the middle and highest part of alJannah, indicates that it has a dome-shape because a thing cannot be at the middle and at its highest point (peak) unless it is round. [See Shaykh-ul-Islam Ibn Taymeeyah’s Al-Fataawaa, vol. 5, pp. 150-155, and the book of Al-‘Arsh by Muhammad Ibn ‘Uthmaan Ibn Abee Shaybah (Riyadh, KSA: Maktabat ar-Rushd (checked by Dr. Muhammad Ibn Khaleefah at-Tameemi), 1418/1998), p. 333].
 This is based upon additional explanation of the translated text which the author, Shaykh Ibn ’Uthaymeen, may Allaah’s Mercy be upon him, directly related to me on Wednesday the 16th of Safar 1419Hj, corresponding to the 10th of June 1998. He stated that this explanation fits with that of the hadeeth on the Firdaws as mentioned above. And Allaah knows best.
Source : From the eBook: Tafseer Ayatul-Kursi – By Shaykh Muhammad bin Saalih Al-’Uthaymeen (rahimahullah). With Related Points of Benefit From the Shaykh’s Commentary on Imaam ibn Taymeeyah’s Sharhul ’Aqeedatil-Waasitiyyah, Prepared by Dr. Saleh As-Saleh (rahimahullah)