Sunan an-Nasa'i #1513 · The Book of Praying for Rain (Al-Istisqa')

Sunan an-Nasa'iIt was narrated that Anas said
Sunan an-Nasa'i · Book 17 · The Book of Praying for Rain (Al-Istisqa')
Sunan an-Nasa'i · كتاب 17 · كتاب الاستسقاء
"The Messenger of Allah (ﷺ) did not raise his hands during any supplication except when praying for rain, when he used to raise his hands so high that the whiteness of his armpits could be seen
أَخْبَرَنِي شُعَيْبُ بْنُ يُوسُفَ، عَنْ يَحْيَى بْنِ سَعِيدٍ الْقَطَّانِ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم لاَ يَرْفَعُ يَدَيْهِ فِي شَىْءٍ مِنَ الدُّعَاءِ إِلاَّ فِي الاِسْتِسْقَاءِ فَإِنَّهُ كَانَ يَرْفَعُ يَدَيْهِ حَتَّى يُرَى بَيَاضُ إِبْطَيْهِ ‏.‏
Reference : Sunan an-Nasa'i 1513In-book reference : Book 17, Hadith 10