مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2623
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه) that The Prophet (ﷺ) offered the sacrifice, then he shaved his head.
Musnad Ahmad 2638Its isnad is saheeh, al-Bukhari (1602) and Muslim (1266)]