Musannaf Ibn Abi Shayba 28:277

Isa ibn Yunus narrated to us, from al-Awza'i, from Hisham ibn Hassan, who said: When Muhammad was asked about whether the martyr should be washed, he would narrate about Hujr ibn Adi when Mu'awiya killed him. He said: Hujr said, "Do not loosen any iron (shackles) from me, and do not wash any blood from me. Bury me in my bonds and my blood; I will meet Mu'awiya on the path tomorrow."