"When the Prophet would prostrate, he placed his nose and his forehead on the ground, and he held his forearms away from his sides, and he placed his hands parallel to his shoulders."  

أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا سَجَدَ أَمْكَنَ أَنْفَهُ وَجَبْهَتَهُ مِنَ الأَرْضِ وَنَحَّى يَدَيْهِ عَنْ جَنْبَيْهِ وَوَضَعَ كَفَّيْهِ حَذْوَ مَنْكِبَيْهِ قَالَ وَفِي الْبَابِ عَنِ ابْنِ عَبَّاسٍ وَوَائِلِ بْنِ حُجْرٍ وَأَبِي سَعِيدٍ