to turn from war to peace; to take instruments, technologies, or money used for war and use them to improve living conditions
—Now that the war is over, we’ll turn our bomb factories into car factories, send our soldiers to college, and find other ways to beat our swords into plowshares.

God’s prophets often said God would punish the people if they did not stop sinning. This punishment sometimes came when God allowed the enemies of both Jewish kingdoms to attack and defeat them, scattering the Israelites as captives to foreign countries. But God also told the prophets that someday he would make peace between the Israelites and their enemies. God told the prophet Isaiah that during this time of peace, the Lord himself

will judge disputes between nations;

he will settle cases for many peoples.

They will beat their swords into plowshares,

and their spears into pruning hooks.

Nations will not take up the sword against other nations,

and they will no longer train for war. (Isaiah 2:4)

A plowshare is the metal blade of a plow, the part that cuts into the soil to prepare it for growing crops.