'Pruning knives' in the Bible

Beat your plough-shares into swords, and your pruning-knives into spears: the weak shall say, I am strong.

And he judged between many peoples, and he admonished to strong nations even to far off; and they beat their swords into ploughshares and their spears into pruning-knives: nation shall not lift up sword against nation, and they shall no more learn war.