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 ‏.‏

It was narrated that Anas said: "The Messenger of Allah (PBUH) 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." Translation Not Available

Book reference: Sunan An Nisai Book 17 Hadith 1513
Web reference: Sunan An Nisai Volume 2 Book 17 Hadith 1514