Caduceus

Ningishzida (Caduceus) sign;
Round an axial staff snakes entwine.
The Asclepius Rod,
Moses raises for God —
The Nehustan — a symbol divine

The Sumerian image of the Ningishzida (ning-ish-ZI-da) is the earliest known symbol of snakes entwined around an an axial rod (reminiscent of a double helix). It predates the Greek image of Caduceus (ca-DU-ce-us) of Hermes, the Asclepius Rod (a-SKLE-pi-us) and the Hebrew Nehustan (ne-HUSH-tan) staff of Moses (these later two symbols having just one snake). All are used as images in traditions of medical practice.

In the case of the Nehustan in the Biblical story of Exodus Moses, to relive the Israelites from snake bites, prays for deliverance. God directs him to create a staff with a symbol of a snake coiled around it, and raises it up and those who see it are cured. Christian theology assigns significance to the event as prefiguring the crucifixion of Christ, who was raised up to cure mankind from the curse of sin (a concept that itself harks back to the Genesis story of the serpent in the Garden of Eden).