On the first day of his journey, Jonah set out into the city and proclaimed, “Forty more days and Nineveh will be overturned!”
Jonah here relates what had briefly been said before, — that he went to Nineveh according to the command of God. He shows then how faithfully he executed the duty enjoined on him, and thus obeyed the word of God. Hence Jonah came and began to enter the city and to preach on the first day.
And Jonah began to enter into the city a day's journey,.... As soon as he came to it, he did not go into an inn, to refresh himself after his wearisome journey; or spend his time in gazing upon the city, and to observe its structure, and the curiosities of it; but immediately sets about his work, and proclaims what he was bid to do...
a day's journey--not going straight forward without stopping: for the city was but eighteen miles in length; but stopping in his progress from time to time to announce his message to the crowds gathering about him. Yet forty days, and Nineveh shall be overthrown--The commission, given indefinitely at his setting out, assumes now on his arrival a definite form, and that severer than before.