وَعَنْ أَنَسٍ
قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَرْفَعُ يَدَيْهِ فِي الدُّعَاءِ حَتَّى يُرى بياضُ إبطَيْهِ
God’s messenger used to raise his hands in supplication so that the whiteness under his armpits was visible.
Mishkat al-Masabih 2154, Book 10, Supplications, Hadith 28. 1 min read