the flawless state of the kustubān (thumb-ring) (1) and the fact that the bow-string leaves no trace upon it. Whoever secures his ring correctly, and whose kustubān remains unharmed by the string’s groove (2), is the most skillful and outstanding of archers.

He went on: Tāhir al-Balkhī (3), Abū Hāshim, Isḥāq, and other senior masters used to keep their kustubāns hidden, never showing them to anyone (4), for fear that a blemish caused by the string (5) might be detected, and they would lose the rank of mastery in the eyes of their peers (6).

He also said: “I spared no effort in searching for an archer whose kustubān showed neither mark nor defect on its face, but I found none.”

Al-Ṭabarī adds: “I asked my teacher (7) to let me see his kustubān, but he refused. I kept pressing him until he consented. Taking it while I watched, he loosed an arrow with it and then handed it to me for inspection (8). I found the draw-track perfectly even—no twist, no tilt—its surface unscathed by the string’s fraying. It was a single band of firm leather (9), with no padding, of moderate thickness.”