Jonah 3:1 Then the word of the LORD came to Jonah a second time: 2 “Go to the great city of Nineveh and proclaim to it the message I give you.”
Jon 3:3 Jonah obeyed the word of the LORD and went to Nineveh. Now Nineveh was a very important city-a visit required three days.
Nineveh was a very important city – Lit. ‘a city great to God’ – utilising a common Heb. superlative. The AV renders this, ‘Now Nineveh was an exceeding great (Heb ‘gadol’) city of three days’ journey.’ This would imply that it was a very large city, which would take three days to travel through. Nineveh itself has been excavated, and its walls are just over 9 miles in circumference. The Heb ‘gadol’ is also used of Gibeon, which is actually quite small. Study of ancient (and modern Bedouin Arab) customs confirms that the reference here is to administrative importance, rather than to physical size. A visit to such a centre customarily took three days: one to arrive, the next the conduct your business, and the third to leave. (Donald Wiseman, A Bible for Today and Tomorrow)
Jon 3:4 On the first day, Jonah started into the city. He proclaimed: “Forty more days and Nineveh will be overturned.”
See how reluctant a prophet Jonah is. His message to Nineveh is terse in the extreme, and does not even mention God’s name.
Jonah 3:5 The Ninevites believed God. They declared a fast, and all of them, from the greatest to the least, put on sackcloth.
Jonah 3:6 When the news reached the king of Nineveh, he rose from his throne, took off his royal robes, covered himself with sackcloth and sat down in the dust.
Jonah 3:7 Then he issued a proclamation in Nineveh: “By the decree of the king and his nobles: Do not let any man or beast, herd or flock, taste anything; do not let them eat or drink.
Jonah 3:8 But let man and beast be covered with sackcloth. Let everyone call urgently on God. Let them give up their evil ways and their violence.
Jonah 3:9 Who knows? God may yet relent and with compassion turn from his fierce anger so that we will not perish.”
Jon 3:10 When God saw what they did and how they turned from their evil ways, he had compassion and did not bring upon them the destruction he had threatened.
‘But is not God said to repent? There seems to be a change in his decree, in Jon 3:10. Repentance is attributed to God figuratively, Nun 23:19. There may be a change in God’s work, but not in his will. He may will a change, but not change his will.’ (Watson, A Body of Divinity, 69)