(51) باب صِفَةِ السُّجُودِ
It was narrated from 'Ubaidullah bin Abdullah bin Aqram that his father said:
"I prayed with the Messenger of Allah (ﷺ) and I used to see the whiteness of his armpits when he prostrated." (ID)
Reference (ID): Sunan an-Nasa'i 1108 (ID)
In-book reference (ID): Book 12, Hadith 80 (ID)
English translation (ID): Vol. 2, Book 12, Hadith 1109 (ID)