Judges 10:8 - Matthew Poole's English Annotations on the Holy Bible

Or, that year they had vexed and oppressed the children of Israel eighteen years. Or, they vexed them in that year, that was the eighteenth year, to wit, of that vexation. This was the eighteenth year from the beginning of that oppression. And these eighteen years are not to be reckoned from Jair's death, because that would enlarge the time of the judges beyond the just bounds, as may appear from 1 Kings 6:1; nor from Jephthah's beginning to reign, because he reigned but six years, and in the beginning thereof put an end to this persecution; but from the fourth year of Jair's reign; so that the greatest part of Jair's reign was contemporary with this affliction. And although this oppression of the Ammonites and Philistines, and the cause of it, the idolatry of the Israelites, be not mentioned till after Jair's death, because the sacred penman would deliver the whole history of this calamity entirely and together; yet they both happened before it; and Jair's death is mentioned before that only by a prolepsis or anticipation than which nothing is more frequent in Scripture. The case of Jair and Samson seem to be much alike. For as it is said of Samson, that he judged Israel in the days of the tyranny of the Philistines twenty years, Judges 15:20, by which it is evident that his judicature and their dominion were contemporary; the like is to be conceived of Jair, that he began to judge Israel, and endeavoured to reform religion and purge out all abuses; but being unable to effect this, through the backwardness and baseness of the people, God would not enable him to deliver the people, but gave them up to this sad oppression; so that Jair could only perform one half of his office, which was to determine differences amongst the Israelites, but could not deliver them from their enemies.