The Apostle of Allah ﷺ said five rak'ahs of the noon prayer and when he completed the prayer, It was said to him: Has there been (commanded) an addition In prayer? He said: What is it? They said: You have said five rak'ahs, so he performed two prostrations.
أَنَّ النَّبِيَّ ﷺ صَلَّى الظُّهْرَ خَمْسًا فَلَمَّا سَلَّمَ قِيلَ لَهُ أَزِيدَ فِي الصَّلاَةِ قَالَ وَمَا ذَاكَ قَالُوا صَلَّيْتَ خَمْسًا فَسَجَدَ سَجْدَتَيْنِ