The Book of Jasher - What is it? Should the Book of Jasher be in the Bible?

TL;DR:

The Book of Jasher was a historical record referenced in Joshua and 2 Samuel but is now lost. Though later writings claimed its name, none are the original or inspired by God, and the Book of Jasher was never part of the biblical canon.

what does the bible say?

The Book of Jasher, mentioned twice in the Old Testament (Joshua 10:13 and 2 Samuel 1:18-27), was an ancient historical record that documented notable events, such as Joshua’s military victory and David’s lament for Saul and Jonathan. While its original text is now lost, later works claiming the name “Book of Jasher” are not connected to the biblical references and are not divinely inspired. The Bible references it as a supplementary source, but it was never regarded as Scripture, nor is there any indication that it was meant to be included in the biblical canon. Its mentions serve to confirm historical events rather than provide authoritative teaching, and even if it existed today, it would not replace or add to the inspired Word of God. The Book of Jasher remains historically interesting but is ultimately secondary to the canonical Scriptures.

from the old testament

The Book of Jasher (or Jashar) is mentioned twice in the Old Testament. The first place is Joshua 10:13: "Is this not written in the Book of Jashar? The sun stopped in the midst of heaven and did not hurry to set for about a whole day." In this account, God had supernaturally caused the sun to be "stopped in the midst of heaven" to allow Joshua and the Israelites the light they needed to win a military victory. Joshua notes that this event was also recorded accurately in the Book of Jasher. He did not state whether all of the Book of Jasher is accurate, its origin, or whether it should be in the Bible.
The Book of Jasher is also mentioned in 2 Samuel 1:18-27. The text contains a lament written by David concerning the deaths of Saul and Saul's son Jonathan. Again, no mention is made of the background of the Book of Jasher. Further, the quote simply notes that this account was also included in another source.

from the new testament

The Book of Jasher is not recorded in the New Testament.

implications for today

In the 1700s a Book of Jasher was published that was alleged to be a translation of the Book of Jasher by Alcuin, an eighth-century British writer. Another work named Pseudo-Jasher and written in Hebrew is dated to the 1600s but is also not connected with the version mentioned in the Old Testament. Though its claim to be the original is inaccurate, its introduction notes other attempts at a Book of Jasher "by Zerahiah Ha-Yevani of the 13th century. There is also known to have been one written by Rabbi Jacob ben Mier of the 12th century, and one by Rabbi Jonahben Abraham of Gerona of the 14th century. We are told of a work by that title from the Amoraim period (3rd to 6th centuries) that is characterized as containing 'for the most part sayings of the sages of the first and second centuries.'" Again, however, the original work of the Book of Jasher is apparently lost and is now only known through its two references in the Bible.

Because the Book of Jasher no longer exists, it clearly cannot be part of the Bible. Yet even if it did exist today, there is no reason to believe it would need to be added to the Bible. The Old Testament writings were already affirmed and had been translated into Greek before the time of Christ. No biblical writer claimed the Book of Jasher was divine; only that it served as another source to confirm two biblical references.

understand

Joshua 10:13 and 2 Samuel 1:18-27 refer to The Book of Jasher as confirmation of the events those passages reference.
The original text of the Book of Jasher is lost, and later works claiming its name are not inspired.
The Book of Jasher was never part of the Bible and served only as a supplementary historical reference.

reflect

How does knowing that the Book of Jasher was a historical reference but not Scripture affect how you view sources outside the Bible?
How does prioritizing canonical Scripture instead of secondary works strengthen your understanding of God’s truth?
What value do secondary works provide for your study of God’s Word?

engage

How does the existence of lost texts like the Book of Jasher shape our understanding of biblical history and context?
What can we learn about biblical authorship and historical record-keeping from the references to the Book of Jasher?
How should we approach texts that claim to be biblical or historical but are not recognized as inspired Scripture?