"No one informed that they saw Messenger of Allah praying Ad-Duha except Umm Hani. She narrated that Messenger of Allah entered her house on the Day of the Conquest of Makkah. He performed Ghusl and performed eight voluntary Rak'ah such that she had not ever seen him pray any Salat lighter than them, but that he completed the bowing and prostrations."
أَنَّهُ رَأَى النَّبِيَّ ﷺ يُصَلِّي الضُّحَى إِلاَّ أُمُّ هَانِئٍ فَإِنَّهَا حَدَّثَتْ أَنَّ رَسُولَ اللَّهِ ﷺ دَخَلَ بَيْتَهَا يَوْمَ فَتْحِ مَكَّةَ فَاغْتَسَلَ فَسَبَّحَ ثَمَانَ رَكَعَاتٍ مَا رَأَيْتُهُ صَلَّى صَلاَةً قَطُّ أَخَفَّ مِنْهَا غَيْرَ أَنَّهُ كَانَ يُتِمُّ الرُّكُوعَ وَالسُّجُودَ