It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Four verses were sent down from a treasure beneath the Throne; nothing other than them was sent down from that treasure: Umm al-Kitab, for Allah says: 'And indeed it is, in the Mother of the Book with Us, exalted and full of wisdom' [Surah al-Zukhruf: 4]; and Ayat al-Kursi; and Surah al-Baqarah; and Surah al-Kawthar."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7889