´Mu’tamir narrated from his father, from Barakah, from Bashir bin Nahik, from Abu Hurairah:` “The Prophet (ﷺ) supplicated for rain (raising his hands) until I saw or one could see the whiteness of his armpits.”
Hadith ReferenceSunan Ibn Majah / Establishing the Prayer and the Sunnah Regarding Them / Hadith: 1271
Hadith Gradingزبیر علی زئی:ضعيف, إسناده ضعيف, سليمان التيمي مدلس و عنعن, و لبعض الحديث شواھد و ھي تغني عن ھذا الحديث, انوار الصحيفه، صفحه نمبر 421