The Scofield Bible Commentary, by Cyrus Ingerson Scofield, [1917], at sacred-texts.com
Book Introduction - Jonah
The historical character of the man Jonah is vouched for by Jesus Christ Mat 12:39-41 as also that his preservation in the great fish was a "sign" or type of the Lord's own entombment and resurrection. Both are miraculous and both are equally credible. Kg2 14:25 records the fulfilment of a prophecy by Jonah. The man himself was a bigoted Jew, unwilling to testify to a Gentile city, and angry that God had spared it. Typically he foreshadows the nation of Israel out of its own land; a trouble to the Gentiles, yet witnessing to them; cast out by them, but miraculously preserved; in their future deepest distress calling upon Jehovah-Saviour, and finding deliverance, and then becoming missionaries to the Gentiles. Zac 8:7-23.
He typifies Christ as the Sent One, raised from the dead, and carrying salvation to the Gentiles. The chapter divisions indicate the analysis of Jonah.