Narrated Ibn Masud:
During the lifetime of Allah's Messenger (ﷺ) the moon was split into two parts; one part remained over the mountain, and the other part went beyond the mountain. On that, Allah's Messenger (ﷺ) said, "Witness this miracle."
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 387
Arabic reference: Book 65, Hadith 4864