This tradition (mentioned above) has also been transmitted by al-Zuhri through a different chain of narrators to the same effect. This version adds:

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.

حَدَّثَنَا عَمْرُو بْنُ عُثْمَانَ، حَدَّثَنَا أَبِي وَبَقِيَّةُ، قَالاَ حَدَّثَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، بِمَعْنَى إِسْنَادِهِ وَحَدِيثِهِ زَادَ وَكَانَ مِنَّا الْمُتَشَهِّدُ فِي قِيَامِهِ ‏.‏ قَالَ أَبُو دَاوُدَ وَكَذَلِكَ سَجَدَهُمَا ابْنُ الزُّبَيْرِ قَامَ مِنْ ثِنْتَيْنِ قَبْلَ التَّسْلِيمِ وَهُوَ قَوْلُ الزُّهْرِيِّ ‏.‏