Narrated Ibn 'Umar:
"The moon was split during the time of the Messenger of Allah (ﷺ). So the Messenger of Allah (ﷺ) said: 'Bear witness.'" (DE)
English reference (DE): Vol. 5, Book 44, Hadith 3288 (DE)
Arabic reference (DE): Book 47, Hadith 3599 (DE)