A mujtahid or the most learned can be identified in one of three ways: 1. a duty-bound person (mukallaf)[2] is certain himself [that someone is a mujtahid or the most learned]. For example, the person is a scholar himself and is able to identify a mujtahid and the most learned; 2.
two learned and dutiful people who are able to distinguish a mujtahid and the most learned confirm that someone is a mujtahid or the most learned, provided that two other learned and dutiful people do not disagree with their statement. In fact, being a mujtahid or the most learned is also established by even one expert (ahl al‑khibrah) whom one trusts; 3. a mukallaf attains confidence (iṭmiʾnān) that a person is a mujtahid or the most learned by rational means.
For example, a group of scholars who are able to distinguish a mujtahid and the most learned and from whose statements one gains confidence confirm that someone is a mujtahid or the most learned.