مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3391
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn ‘Abbas (رضي الله عنه) that When the Prophet (ﷺ) prostrated, the whiteness of his armpits could be seen whilst he was prostrating.
Musnad Ahmad 3414Saheeh because of corroborating evidence; this is a da'eef i