The büdelâʾ (sing. badal; substitutes) are seven individuals. These are people who, by departing from their places within their community, leave behind someone who closely resembles them in their stead. Thus, no one notices their disappearance. Those who are appointed as substitutes in place of another are called büdelâʾ. They are said to be upon the heart (qalb) of Abraham (Ibrahim). (Istilāh, 531; Kāshānī, 36; Jāmiʿ, 78)
The büdelâʾ are not the abdāl. Their number neither increases nor decreases at any time. Their spiritual station (maqām) is characterized by expansiveness (inbisāṭ: breadth, greatness, happiness; expressing the utmost point of specificity with the tongue) in supplication (dua). Their spiritual state (ḥāl) is faith in the unseen (ghayb) and certainty (yaqīn). They are called büdelâʾ because, when one of them is absent, another among them acts as deputy for all. (Nabhānī, I, 45)