مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4331
Musnad of Abdullah bin Mas'ood
It was narrated that `Abdullah said: The moon was split when we were with the Prophet (ﷺ) in Mina, and one half of it went behind the mountain. And The Messenger of Allah (ﷺ) said: "Bear witness."
Musnad Ahmad 4360Its isnad is saheeh, Muslim (2800)]