When the Prophet (ﷺ) prostrated, lie spread out his arms so that the whiteness of his armpits was visible.
Sahih Muslim Book 4, Hadith 267
← Previous Hadith The Messenger of Allah (ﷺ) said. When you prostrate yourself, place the palms of your hands on the ground and raise your elbows.

Sahih Muslim Book 4, Hadith 266 Next Hadith → " When the Messenger of Allah (rtiay peace be upon him) prostrated, he spread out his arms so that the whiteness of his armpits was visible." And in the narration transmitted by al-Laith (the words are:" When the Messenger of Allah (ﷺ) prostrated. he spread his hands from the armpits so that I saw their whiteness."

Sahih Muslim Book 4, Hadith 268