The book contains some dire warnings and prophecies. The King would have done well to listen, but did not. Afterwards, Jeremiah, at God's direction, reconstructs the book from his notes, and sends it back out to the people. Of course, the country ends up in captivity as warned when Babylon takes the city. But, God's word was preserved. It seems that Jeremiah and Baruch weren't only protected and hidden in God's hand. God's words were kept as well.
It is a comforting place to be... hidden in God's hands. No matter the storm that surrounds your little hole in the ground, when you are safe and protected. And, when we hold the Bible in our hands, do we realize we are holding words that went through fire to get to us? Do we know that Jeremiah spent time in a dungeon-like pit in prison for his message? But, how easy it is now to pick up the book and turn the pages... easy for us.