The moon split into two halves during the time of the Messenger of Allah ﷺ, and the Messenger of Allah ﷺ said, "Bear witness."
انشق القمر على عهد رسول الله ﷺ ل شقين، فقال رسول الله ﷺ: اشهدوا
Bukhari narrated it in the Book of Virtues (3636), and Muslim narrated it in the Book of the Description of the Day of Resurrection, Paradise, and Hell (2800), both through the route of Sufyan bin Uyayna, from Ibn Abu Najeeh, from Mujahid, from Abu Muamar, from Abdullah bin Masud, who said, as mentioned above. In another narration recorded by Muslim through a different route, the wording is, "While we were with the Messenger of Allah ﷺ at Mina, the moon split into two halves, one half behind the mountain and the other in front of it. The Messenger of Allah ﷺ said to us, 'Bear witness.'" In another version, he said, "O Allah, bear witness."