question #1 Sahih Muslim 495b, Book 4, Hadith 268 : What is the significance of the Prophet’s physical posture during prostration in prayer?

” 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.”