4 And Jonah began to enter the city on the first day's walk. Then he cried out and said, "Yet forty days, and Nineveh shall be overthrown!"
5 So the people of Nineveh believed God, proclaimed a fast, and put on sackcloth, from the greatest to the least of them. 6 Then word came to the king of Nineveh; and he arose from his throne and laid aside his robe, covered himself with sackcloth and sat in ashes. 7 And he caused it to be proclaimed and published throughout Nineveh by the decree of the king and his nobles, saying, Let neither man nor beast, herd nor flock, taste anything; do not let them eat, or drink water. 8 But let man and beast be covered with sackcloth, and cry mightily to God; yes, let every one turn from his evil way and from the violence that is in his hands. 9 Who can tell if God will turn and relent, and turn away from His fierce anger, so that we may not perish? 10 Then God saw their works, that they turned from their evil way; and God relented from the disaster that He had said He would bring upon them, and He did not do it.
Matthew Henry's Commentary on Jonah 3:4-10
Commentary on Jonah 3:1-4
(Read Jonah 3:1-4)
God employs Jonah again in his service. His making use of us is an evidence of his being at peace with us. Jonah was not disobedient, as he had been. He neither endeavoured to avoid hearing the command, nor declined to obey it. See here the nature of repentance; it is the change of our mind and way, and a return to our work and duty. Also, the benefit of affliction; it brings those back to their place who had deserted it. See the power of Divine grace, for affliction of itself would rather drive men from God, than draw them to him. God's servants must go where he sends them, come when he calls them, and do what he bids them; we must do whatever the word of the Lord commands. Jonah faithfully and boldly delivered his errand. Whether Jonah said more, to show the anger of God against them, or whether he only repeated these words again and again, is not certain, but this was the purport of his message. Forty days is a long time for a righteous God to delay judgments, yet it is but a little time for an unrighteous people to repent and reform in. And should it not awaken us to get ready for death, to consider that we cannot be so sure that we shall live forty days, as Nineveh then was that it should stand forty days? We should be alarmed if we were sure not to live a month, yet we are careless though we are not sure to live a day.
Commentary on Jonah 3:5-10
(Read Jonah 3:5-10)
There was a wonder of Divine grace in the repentance and reformation of Nineveh. It condemns the men of the gospel generation, Psalm 66:18. The work of a fast-day is not done with the day. The Ninevites hoped that God would turn from his fierce anger; and that thus their ruin would be prevented. They could not be so confident of finding mercy upon their repentance, as we may be, who have the death and merits of Christ, to which we may trust for pardon upon repentance. They dared not presume, but they did not despair. Hope of mercy is the great encouragement to repentance and reformation. Let us boldly cast ourselves down at the footstool of free grace, and God will look upon us with compassion. God sees who turn from their evil ways, and who do not. Thus he spared Nineveh. We read of no sacrifices offered to God to make atonement for sin; but a broken and a contrite heart, such as the Ninevites then had, he will not despise.