Abu Hurairah (Ra) narrates that Rasúlullãh (saw) said: For every thing there is a crest, and indeed the crest of the Qur'ãn is Súrah Al-Baqarah. And in it there is a verse, which is the chief of all the verses in the Qur'ãn, and that is Áyatul Kursi.

(Tirmidhí)