Breadcrumb: What book?

Num. 21:14 makes passing reference to the "Book of the Wars of the Lord." We know absolutely nothing about this book other than its mention in the Bible. It seems to have been a factual accounting of the early Israelite wars. Unfortunately, the book has been lost and does not exist today. This is not, however, the only Biblical reference to external sources. It reminds us that for the ancient Israelites, the Bible was just one of several texts used to recount their history.