2 Bible Verses about Books, Metaphorical Use

Then I saw a great white throne and Him who was seated on it, from whose presence earth and sky fled away, no more to be found. I saw the dead, great and small, standing before the throne, and books were opened. Then another book was opened; it was the book of life, And the dead were judged by what was written in the books in accordance with what they had done.

So I went up to the angel and asked him to give me the little book. And he said to me, "Take it and eat it; it will make your stomach bitter, but in your mouth it will taste as sweet as honey." So I took the little book from the angel's hand and ate it all, and in my mouth it did taste as sweet as honey, but when I had eaten it all, it made my stomach bitter.