Musnad Ahmad 1007:98

Ishaq ibn Isa narrated to us, Ibn Lahi'ah narrated to us, from Ubayd Allah ibn Abi Ja'far, from Abd al-Rahman al-A'raj, from Abu Qatadah al-Ansari, that he "killed a man from the disbelievers, so the Messenger of Allah, peace and blessings of Allah be upon him, gave him his spoils and his armor as a gift." He sold it for five awqiyah.