Non-Canonical and Extra-Biblical Books and Letters Mentioned in the Bible

There are at least twenty-one extra-biblical books mentioned in the Bible. Each of these books may have been and probably were consulted by the Holy Spirit-inspired writers of the canonical books.  The Hebrews clearly had many other books than those included in the Bible. Some, such as the Book of Jasher, are mentioned in several verses.

"And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hasted not to go down about a whole day." Joshua 10:13

"(Also he bade them teach the children of Judah the use of the bow: behold, it is written in the book of Jasher.)" 2 Samuel 1:18

Jasher is not the name of a person. This is ספר הישר  Sefer (Book) Ha (the) Yashar (Upright, Correct, Just). The Latin Vulgate translates this as Book of the Just Ones while the Greek Septuagint translates the Hebrew as Book of the Upright.

This lost book was probably a collection of songs and poems about Hebrew battles and heroes. There are several books of Jasher which were composed much later than the biblical period and which are not the book mentioned in the Bible.

1. Sefer HaYashar: A collection of rabbinical theological writings which makes no claim to be the original book.
2. Pseudo-Jasher: ca 1625, a collection of Jewish legends.
3. Book of Jasher: 18th century. Claims to be a translation of the original book but most scholars consider this book to be an eighteenth century forgery.

Numbers

The book of Numbers takes its English name as a translation of the Latin name of the book in the Vulgate, Numeri, and the Greek name of the book in the Septuagent, Αριτημοι. Both names refer to the two numberings in the book, which occur in Chapters 1-4, and in Chapter 26.

Jerome (340? - 420) and Epiphanius (315? - 403) referred to the book as "The Lord Spoke." It was common Jewish practice to name scriptures by their first one or two words. In the case of Numbers, the Jews didn't follow this tradition because the the phrase didn't unambiguously identify the book.

Numbers begins two years after the Israelites escaped from Egypt and ends thirty-eight years later with them looking at the Promised Land from the Transjordan area. The name of the book in the Jewish Bible is b'midhbar (or Bemidbar), which, appropriately enough, means "in the wilderness."