[205] Now at that time bhikkhus were not able to open the door panel. They reported this matter to the Blessed One. "Bhikkhus, I allow a keyhole (tālacchidda). There are three kinds of keys: a metal key, a wooden key, and a horn key." But whoever unfastened these got in, and the dwellings (vihāra) remained unprotected. They reported this matter to the Blessed One. "Bhikkhus, I allow a locking mechanism (yantaka) and a pin (sūcika)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.