Jonah 2:10

If, however, any one imagine it impossible that men should survive for such a length of time, and that Elias was not caught up in the flesh, but that his flesh was consumed in the fiery chariot, let him consider that Jonah, when he had been cast into the deep, and swallowed down into the whale's belly, was by the command of God again thrown out safe upon the land.

Jonah was swallowed by the monster of the deep, in whose belly whole ships were devoured, and after three days he was vomited out again safe and sound. Enoch and Elijah, who even now, without experiencing a resurrection (because they have not even encountered death), are learning to the full what it is for the flesh to be exempted from all humiliation, and all loss, and all injury and all disgrace. They have been translated from this world and from this very cause are already candidates for everlasting life. To what faith do these notable events bear witness, if not to that which ought to inspire in us the belief that they are proofs and documents of our own future and our completed resurrection? To borrow the apostle's phrase, these were "figures of ourselves." They are written that we may believe that the Lord is more powerful than all natural laws about the body.

Jonah then was not ignorant of the mighty hand of God, with which he threatened other men, nor did he imagine that he could utterly escape the Divine power; this we are not to believe: but when he saw the falling away of Israel, and perceived the passing over of the grace of prophecy to the Gentiles-this was the cause of his retirement from preaching and of his delay in fulfilling the command; accordingly he left the watchtower of joy, for this is the meaning of Joppa in Hebrew, I mean his former dignity and reputation, and flung himself into the deep of sorrow: and hence he is tempest-tossed, and falls asleep, and is wrecked, and aroused from sleep, and taken by lot, and confesses his flight, and is cast into sea, and swallowed, but not destroyed, by the whale; but there he calls upon God, and, marvellous as it is, on the third day he, like Christ, is delivered...

Jonah did not escape the sea by the power of his birth, but by the hidden divine command he was thrown overboard, and a whale received him, vomited him out after three days as a sign of future mystery, and reserved him by the merit of prophetic grace.

The prophet is animated with good hope, and now secure about his liberation, he promises that he will sacrifice thanksgiving and that he will fulfill all vows.