2 Only that the generations of the children of Israel might know, to teach them war, at the least such as before knew nothing thereof;
2 (he did this only to teach warfare to the descendants of the Israelites who had not had previous battle experience):
2 It was only in order that the generations of the people of Israel might know war, to teach war to those who had not known it before.
2 He did it to train the descendants of Israel, the ones who had no battle experience, in the art of war.
2 (this was only so that the generations of the children of Israel might be taught to know war, at least those who had not formerly known it),
2 He did this to teach warfare to generations of Israelites who had no experience in battle.
Matthew Henry's Commentary on Judges 3:2
Commentary on Judges 3:1-7
(Read Judges 3:1-7)
As the Israelites were a type of the church on earth, they were not to be idle and slothful. The Lord was pleased to try them by the remains of the devoted nations they spared. Temptations and trials detect the wickedness of the hearts of sinners; and strengthen he graces of believers in their daily conflict with Satan, sin, and this evil world. They must live in this world, but they are not of it, and are forbidden to conform to it. This marks the difference between the followers of Christ and mere professors. The friendship of the world is more fatal than its enmity; the latter can only kill the body, but the former murders many precious souls.