Jonah 3:3 - Matthew Poole's English Annotations on the Holy Bible

So, Heb. And; as God commands and directs, so Jonah with ready, resolved, and obedient mind sets about the work. Jonah arose, and went unto Nineveh; though it was a long journey, yet three weeks or three months travel by land is more eligible than three days in the belly of hell. According to the word of the Lord; every way complying with the command of God, speeding thither resolved to preach whatsoever sermon God should put into his head, encouraged with assurance that God who did send would be with him whithersoever he was sent. An exceeding great city; the greatest city of the known world at that day; it was then in its flourishing state greater than Babylon, whose compass was three hundred and sixty-five or three hundred and eighty-five furlongs, but Nineveh was in compass four hundred and eighty, her walls a hundred feet in height, and broad enough for three coaches to meet and safely pass by each other; it had fifteen hundred towers on its walls, and these towers two hundred feet high; and one million and four hundred thousand men employed continually for eight years to build it, if our author be not mistaken. There is some difference in accounting how this city was three days journey: if we account the length of it at one hundred and fifty furlongs, this will amount to eighteen miles and three quarters; this seems too little to be three days journey, unless it be supposed the prophet accounts his leisurely progress, and takes in the many stops that would necessarily and unavoidably retard him in his walking and preaching such strange news; if we consider this, it is not unlikely six miles would be as far as he could go in a day, preaching to all and discoursing with many. Others will account it three days journey to go through the streets and lanes of this city; but on the supposition it was eighteen miles in length, and eleven miles in breadth, it will be more than three days journey, or a week's journey; for supposing in a mile's breadth but eight streets, from end to end, through eighteen miles length, it will amount to four hundred and sixty-four miles. Others account by the compass of the walls sixty miles, and allow twenty miles to each day's journey, too far for any one to walk, preach, dispute or reason, and account for himself: the first account seems most probable.