“Onely that the generations of the children of Israel might know to teach them warre, at the least such as before knew nothing thereof:)”
1611 King James Version (KJV)
3:2 Teach them war - That by the neighbourhood of such warlike enemies, they might be purged from sloth and security, and obliged them to innure themselves to martial exercises, and to stand continually upon their guard, and consequently to keep close to that God whose assistance they had so great and constant need of.