It is narrated that if somebody asked Imam Mahdi Ahs for a piece of his apparel or footwear, he would say "Take this and use it and do not keep it in the house (as a memento). Even if you wear the skin of this servant (of Allah), you will not achieve salvation (najat) unless you act according to what I have asked you to do."
(Hashia Insaaf Nama - Matan Sharif, N.59)