مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3182
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) came to Dhul-Hulaifah, he entered ihram for Hajj, and he marked his sacrificial animal with a cut on its right side, then he wiped the blood from it, and he garlanded it with two sandals."
Musnad Ahmad 3206Its isnad is saheeh. Muslim (1243)]