It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that during the Battle of the Trench, the Muslims killed a polytheist. They wanted to give wealth in exchange for his corpse, and the Messenger of Allah (peace and blessings be upon him) said regarding this: "Hand over their corpse to them; this corpse is impure and its compensation is also impure." Thus, the Prophet (peace and blessings be upon him) did not accept anything from them in exchange for it.