Musnad Ahmad 25:392

Nasr ibn Bab narrated to us, he said: Al-Hajjaj narrated to us, from Al-Hakam, from Miqsam, from Ibn Abbas, that he said: The Muslims killed a man from the polytheists on the day of the Trench, and they (the polytheists) offered money for his corpse. The Messenger of Allah, peace and blessings of Allah be upon him, said: "Give them their corpse, for it is a foul corpse and a foul blood-money." So he did not accept anything from them.