Steel padlocks typically attached to the grilles of shrines; Iran, 19th-20th century, from the colle
Steel padlocks typically attached to the grilles of shrines; Iran, 19th-20th century, from the collection of Parviz Tanavoli. “Another pilgrimage practice is making a request and a corresponding vow. For example, a pilgrim might pray for success in a business venture and make a vow to pay so much to the shrine if he is successful. As he makes the vow the pilgrim tears off a piece of fabric from his clothing, or takes a piece of wool or thread of some sort, and ties it to the grill. Alternatively he attaches a padlock [like those pictured above] to it. This action signifies the binding of the pilgrim to his intercessor, i.e. the Imam buried there, and acts as a reminder to the intercessor of the pilgrim’s request and promise. Locks are also attached by pilgrims to other grilles, e.g. the steel window in the shrine of the Imam Reza in Mashhad, which faces the tomb chamber and separates it from the outer part of the shrine complex. It is a favourite place to hang locks […].” – James W. Allan, from The Art and Architecture of Twelver Shi'ism Allan notes that these padlocks are but one of two types associated with shrines in Iran. The other type of padlock is “[…] the shrine padlock, which is used to fasten the door of the zarih.” -- source link