I've not seen this myself, but in the Topkapi Museum in Istanbul, they have a very precious goblet. In the center of the inside of that goblet is carved, in gold, a serpent. It has ruby eyes and diamond fangs; its mouth is open and ready to strike. When the goblet is filled with wine, the ruby-red liquid covers the snake. You cannot see it, but as you drink the wine, suddenly the presence of the serpent with all of its menacing appearance is revealed.
Now Jesus, when he came to live life with us, drank the cup of life to the full. But here in Calvary he is at the depths of that cup. And suddenly the serpent, which had been lingering in all of it, through all of it, was revealed in all of its menacing nature. The intensity of evil–and Jesus saw it.