(3) باب رَفْعِ الْيَدَيْنِ فِي الاِسْتِسْقَاءِ
Narrated Anas:
The Prophet (peace be upon him) was not accustomed to raise his hands in any supplication he made except when praying for rain. He would then raise them high enough so much so that the whiteness of his armpits was visible.
Reference: Sunan Abi Dawud 1170
In-book reference: Book 3, Hadith 10
English translation: Book 3, Hadith 1166