مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2311
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: On the day of al-Khandaq, a mushrik man was killed and they asked the Prophet (ﷺ) to let them bury him, and he said: "No, not at all [I cannot please you by doing that]." They said: We will give you something in return for that. He said: "That is even worse."
Musnad Ahmad 2319Its isnad is da'eef]