The Messenger of Allah ﷺ led us in prayer praying two rak'ahs. When he stood up and did not sit (at the end of two rak'ahs) the people stood up along with him. When he finished the prayer and we expect him to give the salutation, he said: "Allah is most great." While sitting and made two prostrations before giving the salutation. Then he gave it.  

أَنَّهُ قَالَ صَلَّى لَنَا رَسُولُ اللَّهِ ﷺ رَكْعَتَيْنِ ثُمَّ قَامَ فَلَمْ يَجْلِسْ فَقَامَ النَّاسُ مَعَهُ فَلَمَّا قَضَى صَلاَتَهُ وَانْتَظَرْنَا التَّسْلِيمَ كَبَّرَ فَسَجَدَ سَجْدَتَيْنِ وَهُوَ جَالِسٌ قَبْلَ التَّسْلِيمِ ثُمَّ سَلَّمَ ﷺ  

Some of us recited the Tashahhud while they were standing. Abu Dawud said: Ibn-Zubair made two prostrations before giving the salutation in a similar way when he stood up at the end of two rak’ahs. This is the opinion of al-Zuhrl.  

عَنِ الزُّهْرِيِّ بِمَعْنَى إِسْنَادِهِ وَحَدِيثِهِ زَادَ وَكَانَ مِنَّا الْمُتَشَهِّدُ فِي قِيَامِهِ