How the Prophet (pbuh) turned his back towards the people [while offering the Salat (prayer) for rain]
حَدَّثَنَا آدَمُ، قَالَ حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنِ الزُّهْرِيِّ، عَنْ عَبَّادِ بْنِ تَمِيمٍ، عَنْ عَمِّهِ، قَالَ رَأَيْتُ النَّبِيَّ صلى الله عليه وسلم يَوْمَ خَرَجَ يَسْتَسْقِي قَالَ فَحَوَّلَ إِلَى النَّاسِ ظَهْرَهُ، وَاسْتَقْبَلَ الْقِبْلَةَ يَدْعُو، ثُمَّ حَوَّلَ رِدَاءَهُ، ثُمَّ صَلَّى لَنَا رَكْعَتَيْنِ جَهَرَ فِيهِمَا بِالْقِرَاءَةِ.
Narrated `Abbad bin Tamim from his uncle: "I saw the Prophet (ﷺ) on the day when he went out to offer the Istisqa' prayer. He turned his back towards the people and faced the Qibla and asked Allah for rain. Then he turned his cloak inside out and led us in a two rak`at prayer and recited the Qur'an aloud in them."