مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1926
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn ‘Abbas said: The Messenger of Allah (ﷺ) was commanded to prostrate on seven (parts) and was forbidden to tuck up his hair and garment.
Musnad Ahmad 1927Sahih (Darussalam) [ al-Bukhari (809) and Muslim (490)]