Jami` at-Tirmidhi Book 47, Hadith 339
"The moon was cleft asunder during the time of the Messenger of Allah (ﷺ), so the Prophet (ﷺ) said to us: 'Bear witness.'"
"The people of Makkah asked the Prophet (ﷺ) for a sign, so the moon was cleft asunder in Makkah two times (meaning two parts), so the following was revealed: 'The Hour has drawn near, and the moon has been cleft asunder, up to his saying: 'Magic, Mustamir (54:1 & 2)' meaning 'Going away.'"
"The moon was split during the time of the Messenger of Allah (ﷺ). So the Messenger of Allah (ﷺ) said: 'Bear witness.'"