SHAFAQNA – In his will to Imam Hassan (AS), Imam Ali (AS) said: Revive your heart (by listening) to preaching ! Of course Imams are infallible and this saying of Imam Ali (AS) is addressed at other people to make them aware of the value of appropriate preaching; and also wants to make it understood that the human being heart can die, and to revive it and keep it alive, must listen to the preaching of those whose hearts are alive; because in our current daily lives we have plenty of causes for the death of our hearts. On the other hand we do not have enough of those whose hearts are alive and can revive hearts, and we are very poor on this account. If we walk an hour in the street, our shoes get dusty, and when we return home, must clean them. Our delicate heart and soul are exposed to many tempting scenes in public places; don’t you think they get dusty and need cleaning? How many tools we have to clean our houses? We do not allow our kitchen or bathroom to get slightly contaminated, then how can we allow our soul and heart which are our human identity to get contaminated, and do not try to purify them, and allow more impurities to enter our hearts and souls ?
 Nahjul Balaghah, Letter 31.
 Banaye Bandegy Safaye Zendegy, Ayatollah Zia Abadi, page 343.