The answer
The Book of Jasher is called in the Septuagint version "the book of the Upright One". It is quoted twice in the Old Testament: Joshua's poetic address to the sun and the moon (Josh 10:12-13) and David's lament for Saul and Jonathan (2 Sam 1:17-27). It was probably a kind of national sacred song-book, a collection of songs in praise of the heroes of Israel, a "book of golden deeds," a national collection.Answered by His Eminence Metropolitan Youssef (opens in a new tab)