A lost work explicitly named inside the Hebrew Bible, known only through biblical references and material apparently attributed to it. Its title survives. The original book does not.
Lost ancient Israelite sourceJoshua 10:132 Samuel 1:18Probably poetic / heroic material
How NLDG is approaching this lost source
Jashar requires a different method from 1 Enoch, Jubilees, or Maccabees because there is no surviving manuscript of the biblical work to summarize. The guide therefore begins with what Scripture actually says, identifies what may reasonably be inferred, and clearly separates the lost source from later books that share its title.
Start here
What does “Book of Jashar” mean?
The Hebrew title is commonly rendered Sefer haYashar, often translated “Book of the Upright” or “Book of the Just.” The word yashar carries the sense of upright, straight, or right.
The Hebrew Bible names the work in Joshua 10:13 and 2 Samuel 1:18. In both contexts, the citation is associated with elevated poetic material about Israel’s heroic past.
Because the original collection has not survived independently, its author, compiler, date, original size, arrangement, and full contents remain unknown.
Joshua 10:12–13
The sun-and-moon poem
During Israel’s battle at Gibeon, Joshua addresses the sun and moon in a short poetic passage. The Hebrew text then refers readers to the Book of Jashar.
The USCCB note understands the citation as pointing to the preceding poem and suggests that Jashar, like the Book of the Wars of the Lord, recounted the exploits of early Israelite heroes in epic style.
The citation therefore gives us our clearest clue about the lost work’s literary character: at least some of its material was remembered in poetic form and connected with national or heroic events.
Textual caution: The ancient Greek Septuagint form of Joshua does not preserve the Jashar citation at this point. That difference belongs to the textual history of Joshua and means the exact history of the citation should not be oversimplified.
2 Samuel 1:17–27
David’s lament for Saul and Jonathan
After Saul and Jonathan die at Mount Gilboa, David composes a lament. The text says that the people of Judah were to be taught “The Bow” and that the piece was recorded in the Book of Jashar.
The lament is unmistakably poetic. Its repeated cry over the fallen warriors, its imagery, and its memorial purpose strengthen the inference that Jashar preserved songs or poems celebrating and mourning major figures and events in Israel’s history.
Unlike a modern archive citation, the biblical notice does not explain whether Jashar was a single-author book, a growing anthology, a court collection, or a later compilation of older material.
What can be inferred?
Probably a collection of remembered heroic poetry
Poetry
Both biblical contexts connect the title with poetic material, making a poetic collection more plausible than a continuous prose history.
National memory
The material concerns Israel’s battles, leaders, grief, and heroic identity.
Possibly composite
Nothing requires one author or one moment of composition. The collection may have accumulated material over time.
Known to biblical writers
The references assume that citing Jashar could identify an earlier source or recognized literary collection.
Not reconstructable
Two biblical references are not enough to rebuild the book’s table of contents, theology, or final shape.
Lost, not hidden
There is no evidence that a complete ancient copy is being withheld. The responsible historical conclusion is that the original work has not survived as an identifiable manuscript.
Textual history
The Greek evidence is not identical to the Hebrew text
The Septuagint version of Joshua 10:13 omits the reference to the Book of Jashar, while the Greek form of 2 Samuel preserves a reference to a “book of the upright.” This variation has generated discussion about when and how the Joshua citation entered the textual tradition.
A possible additional connection has sometimes been proposed in the Greek tradition of 1 Kings 8, but the textual reconstruction is debated and should not be presented as a secure third biblical citation.
Guardrail: NLDG treats Joshua 10:13 and 2 Samuel 1:18 as the standard Hebrew Bible references while acknowledging that ancient textual witnesses complicate the history of the first citation.
The major identification problem
The medieval Sefer haYashar is a different work
A Hebrew midrash also called Sefer haYashar survives and is available today through Jewish libraries and many English reprints. It retells biblical history from creation through later narratives and contains numerous expansions not found in the biblical text.
The surviving printed tradition is early modern / medieval in literary origin. Sefaria identifies it as a midrash and notes that its earliest extant printed version appeared in Venice in 1625, with an introduction claiming an earlier Naples edition.
Its introduction tells a legendary story about the book being preserved from Jerusalem and transmitted through later kingdoms. Those claims belong to that work’s own literary introduction; they are not independent proof that it is the ancient book named in Joshua and Samuel.
A second confusion
Later English “Jasher” publications include known pseudonymous works
The title “Book of Jasher” has also been reused for later English works claiming ancient origins. One eighteenth-century English Pseudo-Jasher was presented as though translated from an ancient manuscript but is recognized as a modern fabrication.
The existence of several unrelated works carrying the same biblical title means title alone proves nothing. A claimed “lost book of the Bible” needs manuscript history, language evidence, provenance, and scholarly textual comparison before any identification can be taken seriously.
Identity check
Three different things called Jashar / Jasher
Biblical Book of Jashar
Ancient and lost
Named in Joshua 10:13 and 2 Samuel 1:18. Probably contained poetic or heroic material. No complete manuscript survives.
Sefer haYashar midrash
Later Jewish literature
An extant midrashic retelling of biblical history, preserved in the early modern printed tradition and widely available today.
English Pseudo-Jasher
Modern pseudonymous publication
A later English work claiming ancient pedigree. It is not evidence for recovering the biblical source.
Canon and reception
Being cited by Scripture is not the same as being a canonical Bible book
Jewish canon
The lost Book of Jashar is not preserved as a separate book of the Tanakh. Joshua and Samuel, which cite it, are canonical.
Roman Catholic canon
Jashar is not a separate canonical Old Testament book. The biblical references are preserved within canonical Joshua and 2 Samuel.
Eastern Orthodox traditions
No extant Book of Jashar is generally received as a separate biblical book in the major Orthodox Old Testament canons.
Protestant traditions
The lost work is not part of the Protestant Old Testament canon. Modern Jasher publications should not be inserted into the canon on the basis of title similarity.
Canon guardrail: Scripture’s citation of another source demonstrates use, not automatic canonical status. Biblical writers also cite royal records, poems, genealogies, and other writings.
Biblical connections
The two secure references
Named source
Joshua 10:12–13
The sun-and-moon poem is followed in the Hebrew text by an explicit reference to the Book of Jashar.
The Septuagint form of Joshua does not preserve the citation, so the textual history should remain visible.
Numbers 21:14 and the Book of the Wars of the Lord
Numbers names another lost collection before quoting poetic material. Together the references show that biblical writers could preserve excerpts from older sources that no longer survive independently.
The original Book of Jashar has not been recovered.
No surviving manuscript can be securely identified as the ancient source cited by Joshua and Samuel.
The medieval Sefer haYashar is not treated as the lost biblical source.
It is valuable Jewish literature in its own right, but its title does not establish ancient identity.
We cannot reconstruct the full lost book from two citations.
Its length, authorship, date, arrangement, and complete contents remain unknown.
“Poetry collection” is an inference, not a surviving table of contents.
The two biblical contexts strongly support a poetic or heroic character, but the genre of the whole work cannot be proven.
Joshua’s textual history is acknowledged.
The absence of the Jashar citation in the Septuagint means readers should not pretend every ancient textual witness is identical.
Citation does not equal canonization.
A biblical writer can use a respected source without declaring the entire source Scripture.
Full-text status
There is no complete ancient Jashar text to reproduce
Lost-source status
NLDG will not publish a modern Jasher book as though it were the lost biblical source.
The only secure access to the biblical Book of Jashar is through the canonical passages that name it and possibly preserve material associated with it. Any later text claiming identity with the lost work must be evaluated by manuscript provenance, language, date, and textual history before that claim is repeated.
