"Just as Jonah became a sign to the Ninevites, so will the Son of Man be to this generation.”
In Catholic theology, typology is the study of types. A type is something (usually, someone) who foreshadows or pre-figures some future thing. A type of a person can foreshadow by means of some personal quality (for example, the physical strength of Samson might be said to foreshadow the spiritual strength of Christ; or the wisdom of Solomon, the Wisdom who is Christ). A person who is a type can also foreshadow through the events of a narrative, as in today’s readings, where the narrative involving Jonah foreshadows the narrative of Holy Week.
Jonah foreshadows Jesus Christ. We see many things about Jonah and the events surrounding him that point to Jesus. But Jesus Himself mentions one thing in particular. He mentions for whom Jonah was a sign: “… Jonah became a sign to the Ninevites.” So will Jesus Himself, he explains, become a sign “to this generation.”
So He is for our generation, also. We can look back, then, to the Ninevites, as if looking in a mirror, and ask how our lives might be reflected in theirs. The Book of the Prophet Jonah is, in fact, very short. It is only four chapters long, and the chapters are 16, 11, 10 and 11 verses long, for a total of just 48 verses! Take some extra time over the next day, then, to read all 48 verses of the Book of Jonah.