Anas bin Malik reported,

He told them that the Messenger of Allah ﷺ would not raise his hands in any of his supplications except during the prayer for rain, when he would raise his hands so high that the whiteness of his armpits became visible.Abu Musa said, "The Prophet ﷺ made supplication and raised his hands, and I saw the whiteness of his armpits."

Bukhari 3565

Sahih

حدثنا عبد الأعلى بن حماد حدثنا يزيد بن زريع حدثنا سعيد عن قتادة أن

أنسا رضي الله عنه

حدثهم أن رسول الله ﷺ كان لا يرفع يديه في شيء من دعائه إلا في الاستسقاء فإنه كان يرفع يديه حتى يرى بياض إبطيه وقال أبو موسى دعا النبي ﷺ ورفع يديه ورأيت بياض إبطيه

البخاري 3565صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Virtues
Chapter
Description of the Prophet ﷺ
Numbering
Darussalam 3565
Bukhari 3565