During the lifetime of the Prophet ﷺ the moon was split into two parts and on that the Prophet ﷺ said, "Bear witness (to thus). (Using translation from Bukhārī 3636)
انْشَقَّ الْقَمَرُ عَلَى عَهْدِ رَسُولِ اللهِ ﷺ شِقَّتَيْنِ فَقَالَ رَسُولُ اللهِ ﷺ «اشْهَدُوا»