The Book of the Wars of the LORD also known as Book of the Wars of Jehovah (Yahweh) is an unknown, non-canonical book referenced in the Book of Numbers. While the book is referenced in the Pentateuch of the Bible's Old Testament, the book is not a part of the Bible. The book was likely a collection of poems describing the God-directed wars and battles of the nation of Israel, similar to that of the also non-canonical book referenced in the Bible, the Book of Jasher. Based off the title it was likely written by an Israelite, and was probably well known among the Hebrew culture at the time. It was probably also compliant with biblical documentation.
It is mentioned once in the Book of Numbers when during a description of the geography of Moab two lines are quoted that give reaffirmation to Numbers. The excerpt is drawn outside the rest of the text and is also inserted in conjunction with Numbers to explain the meaning of those specific lines of the Book.