Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 113

وَعَنِ ابْنِ مَسْعُودٍ قَالَ: انْشَقَّ الْقَمَرُ عَلَى عَهْدِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِرْقَتَيْنِ: فِرْقَةً فَوْقَ الْجَبَلِ وَفِرْقَةً دُونَهُ. فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «اشْهَدُوا» . مُتَّفق عَلَيْهِ

Ibn Mas’ud said that in the time of God’s messenger the moon was split in two portions, one above the mountain and one below it, and God’s messenger said, “Testify.” [*] *A call to the people to testify to his prophetic office, or to the miracle. (Bukhari and Muslim.)