Thabit reported it on the authority of Anas: While leading you in prayer I do not shorten anything in the prayer. I pray as I saw the Messenger of Allah ﷺ leading us. He (Thabit) said: Anas used to do that which I do not see you doing;
when he lifted his head from bowing he stood up (so long) that one would say: He has forgotten (to baw down in prostration). And when he lifted his head from prostration, he stayed in that position, till someone would say: He has forgotten (to bow down in prostration for the second sajda).

حَدَّثَنَا خَلَفُ بْنُ هِشَامٍ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ إِنِّي لاَ آلُو أَنْ أُصَلِّيَ بِكُمْ كَمَا رَأَيْتُ رَسُولَ اللَّهِ ﷺ يُصَلِّي بِنَا . قَالَ فَكَانَ أَنَسٌ يَصْنَعُ شَيْئًا لاَ أَرَاكُمْ تَصْنَعُونَهُ كَانَ إِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ انْتَصَبَ قَائِمًا حَتَّى يَقُولَ الْقَائِلُ قَدْ نَسِيَ . وَإِذَا رَفَعَ رَأْسَهُ مِنَ السَّجْدَةِ مَكَثَ حَتَّى يَقُولَ الْقَائِلُ قَدْ نَسِيَ .