as Salam alaykum.
Let me first bring here Ayat al-Kursi from Quran:
allāhu lā ʾilāha ʾillā huwa l-ḥayyu l-qayyūmu lā taʾkhudhuhū sinatun wa-lā nawmun lahū mā fī s-samāwāti wa-mā fī l-ʾarḍi man dhā lladhī yashfaʿu ʿindahū ʾillā bi-ʾidhnihī yaʿlamu mā bayna ʾaydīhim wa-mā khalfahum wa-lā yuḥīṭūna bi-shayʾin min ʿilmihī ʾillā bi-mā shāʾa wasiʿa kursiyyuhu s-samāwāti wa-l-ʾarḍa wa-lā yaʾūduhū ḥifẓuhumā wa-huwa l-ʿaliyyu l-ʿaẓīmu
Allah—there is no god except Him— is the Living One, the All-sustainer. Neither drowsiness befalls Him nor sleep. To Him belongs whatever is in the heavens and whatever is on the earth. Who is it that may intercede with Him except with His permission? He knows that which is before them and that which is behind them, and they do not comprehend anything of His knowledge except what He wishes. His seat embraces the heavens and the earth, and He is not wearied by their preservation, and He is the All-exalted, the All-supreme.
Let us have a look to book of shia shaykh al-Majlisi “Zaad al-Maad” p 210:
Know that great ablution (qusl) in this day is sunnah muakaddah. As for the type of prayer in the Eid of Ghadir, then famous from it, the one that was narrated from Imam Sadiq (alaihi salam), that he prayed in this day half an hour before dawn of sun two rakats. In each of it he read al-Hamd (surah al-Fatiha), then “Say He is Allah Alone” (surah al-Ikhlas), and “Indeed he revealed it” (surah Qadr), and Ayat al-Kursi till (words) “and they will abode in it forever”, each of them ten times”.
Question is WHERE IN QURAN IN AYAT OF THRONE WORDS “AND THEY WILL ABODE THERE FOREVER”?