It was narrated that Abu Umamah said: The Messenger of Allah (peace and
blessings be upon him) said: “Whoever recites Ayat Al-Kursi immediately after
each prescribed Prayer, there will be nothing standing between him and his
entering Paradise except death.” (Reported by An-Nasa’i and Ibn Hibban.)
Sunnan Nasai’i al Kubra, (6/30), At-Tabrani in his Al-Kabeer (8/114),
Ubayy b. Ka'b said: Allah's Messenger (may peace be upon him) said: O Abu' al-Mundhir, do you know the verse from the Book of Allah which, according to you, is the greatest? I said: Allah and His Apostle (may peace be upon him) know best. He again said: Abu'l-Mundhir, do you know the verse from the Book of Allah which, according to you, is the greatest? I said: Allah, there is no god but He, the Living, the Eternal. Thereupon he struck me on my breast and said: May knowledge be pleasant for you, O Abu'l-Mundhir!
004, Number 1768: (Sahih Muslim)
The Islamic Ummah