مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1961
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn "Abbas that the Messenger of Allah (ﷺ) offered the funeral prayer for the occupant of a grave after he was buried.
Musnad Ahmad 1962Sahih (Darussalam) [ alBukhari (1247) and Muslim (954)]