His paternal uncle had told him that he went out with the Messenger of Allah ﷺ to pray for rain. He turned his rida' around, and turned his back to the people, then he prayed two rak'ahs and recited loudly. (Using translation from Nasāʾī 1509)  

أَنَّهُ «خَرَجَ مَعَ رَسُولِ اللهِ ﷺ يَسْتَسْقِيَ فَحَوَّلَ رِدَاءَهُ وَحَوَّلَ إِلَى النَّاسِ ظَهْرَهُ وَدَعَا ثُمَّ صَلَّى رَكْعَتَيْنِ فَقَرَأَ يَجْهَرُ»  

"The Prophet ﷺ invoked Allah for rain and offered a two rakʿat prayer and he put his cloak inside out." (Using translation from Bukhārī 1026)  

أَنَّ النَّبِيَّ ﷺ «اسْتَسْقَى وَصَلَّى رَكْعَتَيْنِ وَقَلَبَ رِدَاءَهُ»  

The Prophet ﷺ turned his cloak inside out on Istisqa. (Using translation from Bukhārī 1011)  

أَنَّ النَّبِيَّ ﷺ «اسْتَسْقَى فَقَلَبَ رِدَاءَهُ»