It is very important for us to have the exact presentation of the King James Bible, and I believe that this is the Pure Cambridge Edition. There are various King James Bible only teachers who at least prefer the Cambridge, and there are some who say that the Oxford has errors. I believe that the Oxford Edition does contain impurities, and that it is best if we all use the same thing, and that the pure and perfect presentation of the Bible in English is in the Pure Cambridge Edition of the King James Bible.
It is important because every word matters: “Every word of God is pure” (Proverbs 30:5a).
It is important because every letter and punctuation mark matters: “For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.” (Matthew 5:18).
The Pure Cambridge Edition has, at Jeremiah 32:5, “And he shall lead Zedekiah to Babylon, and there shall he be until I visit him, saith the LORD: though ye fight with the Chaldeans, ye shall not prosper?” But the Oxford Edition has “prosper.” This seems like a minor difference. But it is major. It is major because the very correctness of the Word of God is at stake.
Now, the reason why the verse should end with a question mark is because in verse three we read that Zedekiah said, “Wherefore dost thou prophesy, and say ...” and then the rest of verse three to the end of verse five is his quote of the prophecy, but he is asking “Wherefore”, that is, Why do you say this?
Since “Wherefore” is the beginning of the question, the end of the question should have a question mark, as is given at the end of verse five.
All the editions which do not have a question mark at the end of verse five are impure presentations. That includes the 1611 Edition. The Word of God is pure, but obviously it took some time before the King James Bible was being printed exactly correct in regards to all the spelling and little printer's mistakes.
(There are other places where the Scripture shows that quotations are given as part of questions, such as Mark 12:10, 11.)