There has been a long-standing association between the Prophet Jonah and the mythological figure of Oannes, not only because the two names are so similar from an etymological point of view, but chiefly because this deity was depicted as a man adorning fish-like garments, almost as if he is emerging out the fish itself. The Babylonian historian Berossus describes Oannes as a half man, half fish creature below:
Share“A man, or rather a monster, Half man and half fish, coming from the sea, appeared near Babylon; he had two heads; one, which was the highest, resembled that of man, the other that of a fish. He had the feet of a man, and the tail of a fish; and his speech and voice resembled that of a man: a representation of him is still preserved. This monster dwelt by day with men, but took no food; he gave them knowledge of letters, arts, and sciences; he taught them to build towers and temples; and to establish laws; he instructed them in the principles of geometry; taught them to sow, and to gather the fruits of the earth; in short, whatever could contribute to polish and civilize their manners. At sun set he retired to the sea, in which he passed the night. There appeared likewise others of the same species.”
According to Mesopotamian mythology, Adapa/Oannes was a mortal man and a son of the god Ea, and was instrumental in bringing the arts of civilisation to humanity. In a further parallel to the story of Jonah and the fish, we are told that while Adapa was out fishing one day, his boat was overturned by Ninlil, the personification of the South Wind. Indeed, the similarities between the story of Jonah and the figure of Oannes run so deep, that many commentators have erroneously proposed that these legends were originally inspired by the events surrounding the Prophet Jonah himself. This misconception is recounted in the Wikipedia article concerning Jonah:
Biblical scholars have speculated that Jonah may have been in part the inspiration behind the figure of Hannes in late Babylonian mythology. The deity name "Oannes" first occurs in texts from the Library of Ashurbanipal (more than a century after the time of Jonah) as Uanna or Uan but is assimilated to Adapa, a deity first mentioned on fragments of tablets from the 15th or 14th century BC found in Amarna in Egypt. Oannes is described as dwelling in the Persian Gulf, and rising out of the waters in the daytime and furnishing humanity instruction in writing, the arts and the various sciences. Berossus describes Oannes as having the body of a fish but underneath the figure of a man—a detail that, some biblical scholars suggest, is not derived from Adapa but is perhaps based on a misinterpretation of images of Jonah emerging from the fish. (See here)
However the various myths concerning the figure of Adapa predate the ministry of Jonah by several centuries, and can be traced as far back as the 14th century BC. Although the connection between the events behind the story of Jonah and the figure of Oannes would not have went unnoticed by the Assyrians themselves, and it is quite probable that the ancient Ninevites would have associated the appearance of the prophet emerging from the fish with the myth of Adapa. It is even possible that the later name "Oannes" used for Adapa is itself derived from Jonah, because of this close association.
Given the fact that the engraving found in Kizkapan Cave is based upon earlier imagery associated with Adapa/Oannes, it makes it more likely that this relief depicts events which took place during the Bur-Sagle Eclipse of 763BC, rather than the Eclipse of Thales. As such, the two figures laying down weapons may represent a cessation in hostilities during the revolts that were unfolding in Nineveh, which were recorded as taking place around this time by the Assyrian Eponym Canon. Actions which were prompted by the appearance of the eclipse itself, and a prophet who emerged out of a fish to announce the destruction of Nineveh.
Given the possibility that the repentance of the Ninevites at the preaching of Jonah can be attributed to the Bur-Sagle Eclipse, we have some grounds to suggest that the original "sign of Jonah" consisted of the appearance of a total solar eclipse over the site of ancient Nineveh. When we look to Christ's statement concerning the appearance of the "sign of Jonah" to a wicked and perverse generation, we find that these words were made immediately after His discourse on the binding of the strong man - which according to St. Augustine of Hippo, is an integral component of the prophecy of the unbinding of Satan at the end of the "thousand years" mentioned in Rev 20:
The Lord Jesus Christ Himself says,No man can enter into a strong man's house, and spoil his goods, except he first bind the strong man— meaning by the strong man the devil, because he had power to take captive the human race; and meaning by his goods which he was to take, those who had been held by the devil in various sins and iniquities, but were to become believers in Himself. It was then for the binding of this strong one that the apostle saw in the Apocalypsean angel coming down from heaven, having the key of the abyss, and a chain in his hand. And he laid hold,he says,on the dragon, that old serpent, which is called the devil and Satan, and bound him a thousand years,— that is, bridled and restrained his power so that he could not seduce and gain possession of those who were to be freed. (St. Augustine of Hippo, City of God XX:7)
So in relation to the sacrificial death of Jesus and His resurrection on the third day, the "sign of Jonah" harks back to the three days the prophet spent in the belly of the fish. An event which foreshadowed the crucifixion, burial and resurrection of Christ - which in turn brought about the binding of Satan. (Read more.)