Sunan an Nasai 1509
The Book of Praying for Rain (Al-Istisqa')
أَخْبَرَنِي عَمْرُو بْنُ عُثْمَانَ، قَالَ حَدَّثَنَا الْوَلِيدُ، عَنِ ابْنِ أَبِي ذِئْبٍ، عَنِ الزُّهْرِيِّ، عَنْ عَبَّادِ بْنِ تَمِيمٍ، أَنَّ عَمَّهُ، حَدَّثَهُ أَنَّهُ، خَرَجَ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم يَسْتَسْقِي فَحَوَّلَ رِدَاءَهُ وَحَوَّلَ لِلنَّاسِ ظَهْرَهُ وَدَعَا ثُمَّ صَلَّى رَكْعَتَيْنِ فَقَرَأَ فَجَهَرَ .
It was narrated from Abbad bin Tamim that :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
Grading: Abu Ghuddah: Sahih · Al-Albani: Sahih · Zubair Ali Zai: Sahih - Agreed Upon
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.