Narrated Abu Hurairah:
that the Messenger of Allah (ﷺ): "For everything there is a hump (pinnacle) and the hump (pinnacle) of the Qur'an is Surat Al-Baqarah, in it there is an Ayah which is the master of the Ayat in the Qur'an; [it is] Ayat Al-Kursi." (DE)
English reference (DE): Vol. 5, Book 42, Hadith 2878 (DE)
Arabic reference (DE): Book 45, Hadith 3119 (DE)