Hadith.388 - The Imam عليه السلام said:
"Whoever washes a deceased believer and fulfils the trust in that act, Allah سبحانه وتعالى will forgive them." It was asked: "How does one fulfil the trust in this matter?"
Imam عليه السلام replied: "By not disclosing what they see and maintaining their duty until the deceased is buried."