Jeremiah 39:12 - Matthew Poole's English Annotations on the Holy Bible

It is more than probable that Nebuchadrezzar had been informed by some of the chief commanders of his army, who had it from some of the Jews that had escaped out of the city to the Chaldean army, that Jeremiah had constantly told the king and the nobles that the Chaldeans should take the city, and as steadily persuaded both the king, and princes, and people to surrender it to them, and prevent the effusion of blood; and that he was imprisoned for this, and had been a great sufferer that way; and that this made, this heathen prince so kind to the prophet as to give this order. In the mean time the hand of God is to be taken notice of, who undoubtedly put this into the heart of this pagan prince; and we may learn that none shall lose any thing at last by being faithful to the commands of God, though they may be for the present losers. What we translate, look well to him, is in the Hebrew, set thine eyes upon him; and expounded by the following words, commanding him to do him no harm, and to give or grant to him whatever he desired.