Muwatta Imam Malik Book of Prayer, Hadith 70

Yahya related to me from Malik from Ibn Shihab from al-Araj that Abdullah ibn Buhayna said, "The Messenger of Allah ﷺ prayed two rakas with us and then stood without sitting and the people stood with him. When he had finished the prayerand we had seen him say the taslim, he said 'Allah is greater' and did two sajdas from the sitting position and then said the taslim again."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنِ الأَعْرَجِ، عَنْ عَبْدِ اللَّهِ ابْنِ بُحَيْنَةَ، أَنَّهُ قَالَ صَلَّى لَنَا رَسُولُ اللَّهِ ﷺ رَكْعَتَيْنِ ثُمَّ قَامَ فَلَمْ يَجْلِسْ فَقَامَ النَّاسُ مَعَهُ فَلَمَّا قَضَى صَلاَتَهُ وَنَظَرْنَا تَسْلِيمَهُ كَبَّرَ ثُمَّ سَجَدَ سَجْدَتَيْنِ وَهُوَ جَالِسٌ قَبْلَ التَّسْلِيمِ ثُمَّ سَلَّمَ .