This kind of structure for locks is found in depictions of bas-reliefs in the Luxor Temple, in Upper Egypt, but many scholars believe that the origin is much older and they date them back to the Sumerians.
 
The lock is composed of several elements that differ both in practical use and in symbolic meaning.
Such as the vertical element, called the body that mechanically houses the other elements inside. From the symbolic point of view on the top of it are represented the most powerful symbols carved in the round, in this case two birds, while the lower part of the same is exploited for symbolic and decorative figurations.
 
The locks and doors are made by professional artisans, often framed in closed societies, which preserve and transmit the esoteric and material knowledge necessary for the correct execution of the works.
The "forgeron", that is the blacksmith-sculptor, is in fact a sort of demiurge between the visible and the invisible, between man and the divine, and it is for this reason that the profession is much sought after and is not easy to become such, if not after an appropriate period of apprenticeship.