Sahih Muslim
The Book Giving Description of the Day of Judgement, Paradise and Hell (Kitab Sifat Al-Qiyamah wal Janna wan-Nar)
Book Number: 039 / Hadith Number: 6729
Anas reported that the moon was split up in two parts and in the hadith recorded in Abu Dawud, the words are:" The moon was split up into two parts during the life of Allah's Messenger (may peace be upon him)."