أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ الْمَرْوَزِيُّ، قَالَ أَنْبَأَنَا شَرِيكٌ، عَنْ أَبِي إِسْحَاقَ، قَالَ وَصَفَ لَنَا الْبَرَاءُ السُّجُودَ فَوَضَعَ يَدَيْهِ بِالأَرْضِ وَرَفَعَ عَجِيزَتَهُ وَقَالَ هَكَذَا رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَفْعَلُ .
It was narrated that Abu Ishaq said: "Al-Bara' described the prostration to us. He places his hands on the ground and raised his posterior and said: 'This is what I saw the Messenger of Allah (PBUH) doing." Translation Not Available
Book Ref: Sunan An Nisai Book 12 Hadith 1104
Web Ref: Sunan An Nisai Vol 2 Book 12 Hadith 1105