[Machine] Narrated Maymuna bint Al-Harith, the wife of the Prophet Muhammad ﷺ , said, "When the Messenger of Allah ﷺ prostrated, his back would become hollowed and his armpits would widen open."
عَنْ مَيْمُونَةَ بِنْتِ الْحَارِثِ زَوْجِ النَّبِيِّ ﷺ قَالَتْ كَانَ رَسُولُ اللهِ ﷺ «إِذَا سَجَدَ جَافَى حَتَّى يُرَى خَلْفُهُ وَفَتَحَ إِبْطَيْهِ»