مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2581
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn ‘Abbas (رضي الله عنه) from the Prophet (ﷺ) that he said: "I have been commanded to prostrate on seven and not to tuck up my hair or garment.”
Musnad Ahmad 2596Its isnad is saheeh, al-Bukhari (809) and Muslim (490)]