Sahih Bukhari Volume 9, Book 93, Hadith Number 511.

Narrated By ‘Abdullah : A man from the people of the scripture came to the Prophet and said, “O Abal-Qasim! Allah will hold the Heavens upon a Finger, and the Earth on a Finger and the land on a Finger, and all the creation on a Finger, and will say, ‘I am the King! I am the King!’ “I saw the Prophet (after hearing that), smiling till his premolar teeth became visible, and he then recited: “No just estimate have they made of Allah such as due to him…” (39.67)