Musnad Ahmad 1242:5

'Affan narrated to us, he said: Hammad ibn Salamah narrated to us, he said: Thabit narrated to us, from Salih Abu Hujayr, from Mu'awiyah ibn Hudayj—and he had companionship [with the Prophet]—who said: "Whoever washes a deceased person, shrouds him, follows him [in the funeral procession], and takes charge of his corpse, returns forgiven." Abu 'Abd al-Rahman said: My father said: It is not *marfu'* [attributed to the Prophet].