Hadith 6:200
Waki' narrated to us, he said: Shu'bah narrated to us, from Qatadah, from Sa'id ibn al-Musayyib and al-Hasan, that they both said: "The martyr is washed; no one dies except that he becomes in a state of major ritual impurity (janabah)."
حدثنا وكيع قال نا شعبة عن قتادة عن سعيد بن المسيب والحسن انهما قالا الشهيد يغسل ما مات ميت إلا أجنب