There was an eclipse of the sun. The Messenger of Allah ﷺ commanded a man who summoned: "The prayer will be held in congregation"  

كُسِفَتِ الشَّمْسُ فَأَمَرَ رَسُولُ اللَّهِ ﷺ رَجُلاً فَنَادَى أَنَّ الصَّلاَةَ جَامِعَةٌ