Greatest Verse of All
Hazrat Ubayy (ra) bin Kaab relates:
“The Holy Prophet (sa) stated, ‘O Abu Munzir, do you know which verse in Allah’s book that has been granted to you is the greatest of all?’ I submitted, ‘Allah and His Messenger (sa) know better.’ The Holy Prophet (sa) again asked, ‘O Abu Munzir, do you know which verse in Allah’s book that has been granted to you is the greatest of all?’ I gave the same response, but when the Holy Prophet (sa) asked again, I stated:
اَللّٰهُ لَآ اِلٰهَ اِلَّا هُوَ الْحَيُّ الْقَيُّوْمُ
[Allah – there is no God but He, the Living, the Self-Subsisting and All-Sustaining. (Ch.2: V.256)]
Hazrat Ubayy (ra) states, “The Holy Prophet (sa) placed his hand upon my chest and stated, ‘By God, O Abu Munzir, may your knowledge be a source of blessing for you.’”
(Sahih Muslim, Kitab Salat al-Musafirin wa Qasriha, Bab Fadl Surat al-Kahf wa Ayat al-Kursi, Translation of Nur Foundation, Vol. 3, p. 300.)
In other words, the Holy Prophet (sa) expressed his approval to his answer.