Attendance registers (tibaq or sama‘at) are ubiquitous in medieval hadith manuscripts; their functions have, however, received little attention and have often been misunderstood in the secondary literature. The audition register was originally developed to record the attendance of adults who had heard an unvocalized text read aloud by a master and could therefore, theoretically, transmit the text accurately to the following generation. By the close of the fourth/tenth century the hadith corpus had been canonized and was no longer thought to require the careful preservation it once had. Although no longer needed for the preservation of hadith, the paradigm of oral hadith transmission was maintained as a means of transmitting religious capital and scholarly authority. The cultivation of short chains of transmission (isnads), which was originally prized as a means of avoiding mistakes in transmission, increasingly became an end in itself and replaced preservation as the primary mark of quality in hadith transmission. The attendance register was adapted to serve this aim. By having infants and young children hear a hadith text read aloud in the presence of an elderly authority, several links could be eliminated from the isnad. Infants and young children who attended a hadith reading were, of course, unlikely to remember much, if anything, about the reading fifty or more years later when the time came for them to transmit what they had ‘heard.’ The attendance register offered a solution to this problem and the attendance of children and infants began to be recorded in attendance registers. A child who was recorded in a register for a reading of al-Bukhari’s Sahih at four years old and lived to old age would possess a short isnad and would be highly sought after as a result. Drawing on a variety of both published and manuscript sources, this paper explores this function of the attendance register through the case of an obscure elderly illiterate stone mason, Abu ‘Abbas al-Hajjar, who upon having his name discovered in an attendance register for a reading of al-Bukhari, which took place close to a century earlier, rose to fame and fortune, receiving large sums to go on tour throughout the Mamluk realm and transmitting to the foremost hadith authorities of his time. As a result of his discovery in this attendance register al-Hajjar became a central link in almost all latter chains of transmission from Fez to Istanbul, to Delhi.