What Scripture says
The Book of Jashar (“the Upright” or “the Just”) is mentioned twice:
- After the sun stands still at Gibeon: “Is this not written in the Book of Jashar?” (Joshua 10:13, ESV).
- Before David’s lament for Saul and Jonathan, known as the Song of the Bow: “and he said it should be taught to the people of Judah; behold, it is written in the Book of Jashar” (2 Samuel 1:18).
Both times, the biblical writer quotes a poem and points to Jashar as where it can be found. Some scholars think a third reference survives in the Greek translation of 1 Kings 8:53, in Solomon’s prayer.
What the evidence says
History
What it was
The two passages suggest Jashar was a collection of poems or songs celebrating Israel’s heroes and battles, perhaps compiled in the early monarchy. Both quotations are poetry: Joshua’s command to the sun and moon, and David’s lament (“How the mighty have fallen!”, 2 Samuel 1:19). The writers of Joshua and Samuel used it the way a historian uses a source. That doesn’t make the collection itself Scripture, just as quoting a poet doesn’t (see 3.5).
The original collection hasn’t survived.
The modern “Book of Jasher”
Several later books have been given the name, and are sold or shared online today:
| Book | Origin | Status |
|---|---|---|
| Sefer haYashar (midrash) | A medieval Hebrew retelling of Genesis to Judges, printed in the 1500s–1600s; English translation 1840 | A legendary expansion, not the ancient book |
| Jacob Ilive’s Book of Jasher | Published in 1751, claiming to be translated by the medieval scholar Alcuin | A forgery |
| Other works | Various | Unrelated to the biblical source |
The most widely circulated version is the 1840 English translation of Sefer haYashar. Scholars who have examined it find medieval Hebrew vocabulary, dependence on medieval Jewish commentaries (midrash), and many anachronisms. No serious scholar believes it is the book Joshua and Samuel quote.
Where they meet
Jashar shows that biblical writers used older sources openly and named them. The collection was never presented as Scripture, and nothing suggests it was meant to be.
What’s still open
What else the original collection contained.
Bottom line
Jashar is quoted in Joshua 10:13 and 2 Samuel 1:18: a collection of songs the writers drew on, never Scripture itself. The “Book of Jasher” sold today is a much later work, not the lost book. This is rated Settled.