From Gotquestions.org: “Also known as the ‘Book of the Upright One’ in the Greek Septuagint and the ‘Book of the Just Ones’ in the Latin Vulgate, the Book of Jasher was probably a collection or compilation of ancient Hebrew songs and poems praising the heroes of Israel and their exploits in battle. The Book of Jasher is mentioned in Joshua 10:12-13 when the Lord stopped the sun in the middle of the day during the battle of Beth Horon. It is also mentioned in 2 Samuel 1:18-27 as containing the Song or Lament of the Bow, that mournful funeral song which David composed at the time of the death of Saul and Jonathan.”
Here is one of a number of books that contain Biblical truth but that are not inspired wholly. They are good for quoting and a certain amount of edification, but cannot be relied upon as from God in their entirety.
As to whether that book is available today, there are actually several variant versions out there, but none that date before 100 A.D. Since Jasher was not considered an inspired canonical book, its preservation was not a top priority of Jewish scholars and religious.
Joshua 11:13. Why did Israel stop short of burning cities on the “mounds” ?
Commentators collectively agree that the “mounds” here are simply the high place upon which ancient cities were built, for protection. Joshua decided to keep these well-built cities in place, so as to be populated by Israel when the time came. No need to destroy everything, if there was a future use.
JUDGES
Judges 1:1-2. How was the Lord approached here, and how did he answer?
In the absence of any prophet of God [at least the text is silent about such a man] it would seem that the leadership would have approached the High Priest (Eleazar or perhaps Phinehas by now), and the High Priest would have used the special revelation of Urim and Thummim, discussed earlier. It is unclear from Scripture how this mechanism worked, but that it was viewed as a way of communicating with Heaven, is certain.
Judges 1:19, 27; 2:21-23. What reasons are given here for not totally wiping out certain Canaanites? What happened instead?
The people of God said that iron chariots or fierce determination on the part of the enemy kept them from completing the task. God’s own reason for slowing things down is given later. He decided to leave certain of the enemies nearby as a way to test His people’s devotion to Him.
But they failed the test. They soon learned the way of the heathen and had to be chastised severely. At that point they called on God for a deliverer, which was given, only to fall back into idolatry when the deliverer was off the scene.
Judges 7:3. What do Gideon’s practices recall from the words of Moses?
Deuteronomy 20: 8 “Then the officers shall speak further to the people and say, ‘Who is the man that is afraid and fainthearted? Let him depart and return to his house, so that he might not make his brothers’ hearts melt like his heart.’ “
One cannot help but think that this Deuteronomy passage, which includes passes for people building a house, marrying a wife, etc, must have been on the minds of those would-be disciples of Jesus who requested a leave of absence based on some of these items, when Jesus invited them to follow Him. They did not realize that a greater than Moses called them to serve.
Judges 8:27. What is an ephod, and why worship it?
In this case, an ephod was a sleeveless coat worn by the high priest. It was beautifully adorned with colorful materials and jewels. In the high priest’s garment was also the precious Urim and Thummim, which we have referenced above. Whether Gideon’s intention was to replicate the original priestly garment and thus set up a parallel worship center, or simply to create a civil remembrance of the true, which people could see and relate to Israel’s past, we are not informed. Certainly there was reason for Gideon to believe that God was present in his life, and a reality in the victories He had secured for His people, but would he have gone this far, certainly knowing that the High Priest would not bless such a move.
But whatever Gideon’s motivation, the easily distracted people of the days of the judges took it as a signal to depart from the ways of the Lord yet again. Here was a ready-made visible object of worship with the scent of the God of Israel all over it. Like the other objects of worship hiding in many of their tents, this one certainly deserved a special place in their hearts. This was the calf in the wilderness all over again. No need to go to the pagan places of worship when God Himself was now providing a short-cut to temple worship via their new hero, Gideon.
Such are God’s people in every generation. So willing to follow the latest fad that comes around, so easily ensnared by the false winds of excitement.