Volume 5 · Book 58 · Hadith 208
Narrated Anas bin Malik: The people of Mecca asked Allah's Apostle to show them a miracle. So he showed them the moon split in two halves between which they saw the Hiram' mountain.
— Sahih Bukhari, Volume 5, Book 58: Merits of the Helpers in Madinah (Ansaar), Hadith #208