Musnad Ahmad 33:77

Muhammad—meaning Ibn Ja'far—narrated to us, Shu'bah narrated to us, I heard 'Abd Rabbih narrating from al-Zuhri, from Ibn Jabir, from Jabir ibn 'Abd Allah, from the Prophet, may Allah bless him and grant him peace, that he said regarding the slain of Uhud: "Do not wash them, for every wound—or every drop of blood—will emit the fragrance of musk on the Day of Resurrection." And he did not perform the funeral prayer over them.