Judges 3:2

English Standard Version

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. 

New International Version

2 (he did this only to teach warfare to the descendants of the Israelites who had not had previous battle experience): 

New International Reader’s Version

2 He wanted to teach the men in Israel who had never been in battle before. He wanted them to learn how to fight. 

King James Version

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;