'Book' in the Bible

Then the LORD told Moses, "Write this in a book as a memorial and recite it to Joshua: "I'll certainly wipe out the memory of the Amalekites from under heaven.'"

He took the Book of the Covenant and read it to the people. They said, "We will put into practice and obey everything that the LORD has decreed."

Now, if you will, forgive their sin but if not, blot me out of your book which you have written."

The LORD told Moses, "Whoever sins against me, I'll blot him out of my book.