Jami` at-Tirmidhi Book 47, Hadith 338
"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.'"
"We were with the Messenger of Allah (ﷺ) in Mina, when the moon was cleft asunder into two parts. Part of it was behind the mountain, and part of it before it. The Messenger of Allah (ﷺ) said to us: 'Bear witness' meaning: The house has drawn near, and the moon has been cleft asunder (54:1)."
"The moon was cleft asunder during the time of the Messenger of Allah (ﷺ), so the Prophet (ﷺ) said to us: 'Bear witness.'"