Today the Church commemorates the Prophet Jonah (8th c. BC). Jonah was viewed by Christian commentators as prefiguring the salvation brought about through Jesus Christ. Jesus Himself in Matthew 12:39-41 points to Jonah as a prophetic sign of His death and resurrection. St Irenaeus, writing in the late 2nd Century, sees the Jonah story as explaining what has happened to all of humanity – Satan or Death is the whale who swallows not just Jonah but all of humanity (in the quote below, Jonas is the Greek version of the name Jonah).
In the same way, from the beginning, God permitted humanity to be swallowed up by the great whale who was the author of the transgression, not that they be swallowed up and perish altogether; no, God, through the miracle of Jonas, planned the method of salvation that was effected by the Word for those who possess the same teaching about the Lord as Jonas, and confessed and said, I am a servant of the Lord, and I fear the Lord, the God of heaven, who made the sea and the dry land (Jonah 1:9). Thus humankind, receiving from God the salvation it could not have hoped for, might rise from the dead, glorify God, and utter the cry that was prophesied by Jonas, I called out to the Lord from my distress, and He answered me from the belly of hell (Jonah 2:2). Thus he might also always continue [to live], glorifying God and rendering thanks to Him unceasingly for the salvation he has received from Him. (AGAINST THE HERESIES Vol 3, p 95)
The narrative of Jonah and the whale is thus an allegory of human history—we all were being swallowed by the whale (= death or the devil) until Christ rescued us. Additionally, it represents the story of each of us: each human’s life is understandable by studying the story of Jonah as our relationship to death. It is also a prophecy of the death and resurrection of the Messiah.