How, then, did the idea come into existence that Jesus did not die upon a simple gallows, but rather upon wood having the well-known form of the cross? It arose out of a misunderstanding, from considering as the same and mingling two ideas which were originally distinct but described by the same word wood, tree, xúlon, lignum, arbor. This word signifies, as we have already said, on the one hand indeed the stake or gallows (staurós, crux) upon which the criminal was executed; but the same word, corresponding to the Hebrew text of the Old Testament, also referred to the "wood," "the tree of life," which was supposed to stand in Paradise. According to the Revelation of John it was to serve as food for the holy in the new Paradise to come, [267] and it was honoured by the Christians as the "seal" and guarantee of their salvation under the form of the mystic cross or Tau. In all private religious associations and secret cults of later antiquity the members made use of a secret sign of recognition or union. This they carried about in the form, in some cases, of wooden, bronze, or silver amulets hung round the neck or concealed beneath the clothes, in others woven in their garments, or tattooed upon the forehead, neck, breast, hands, &c. Among these signs was the cross, and it was usually described under the name "Tau," after the letter of the old Phoenician alphabet. Such an application of the cross to mystic or religious ends reaches back into grey antiquity. From of old the cross was in use in the cult of the Egyptian Gods, especially of Isis and Horus. It was also found among the Assyrians and Persians, serving, as the pictures show, in part as the mark and ornament of distinguished persons, such as priests and kings, in part also as a religious attribute in the hands of the Gods and their worshippers. According to some it was the sign which Jahwe ordered the Israelites to paint upon their doors with the blood of the lamb when he sent the angel of death to destroy the first-born of their Egyptian oppressors. It played a similar part also in Isaiah [268] and Ezekiel, [269] when it was a question of separating the god-fearing Israelites from the crowd of other men whom Jahwe purposed to destroy. When the Israelites were pressed in battle by the Amalekites Moses is said to have been helped by Aaron and Hur to stretch out his arms in the shape of that magic sign, and thus to have rendered possible a victory for his people over their enemies. [270] Among the other nations of antiquity also--the Greeks, Thracians, the Gaulish Druids, and so on--the Tau was applied in a similar manner to ritualistic and mystic ends. It appears as an ornament on the images of the most different divinities and heroes--e.g., Apollo, Dionysus, Demeter, Diana (the Phoenician Astarte). It is also found upon innumerable Greek, Roman, Egyptian, and Phoenician coins, upon vases, pictures, jewellery, &c. In Alexandria the Christians