Nations

Riddle: A harvest sown and reaped on the same day In an unplowed field, Which increases without growing, Remains whole though it is eaten Within and without, Is useless and yet The staple of nations. What is it?

Answer: War.

Source: https://www.riddles.com/964

A harvest sown and reaped on the same day In an unplowed field, Which increases without growing, Remains whole though it is eaten Within and without, Is useless and yet The staple of nations.
What is it? — Nations by Anonymous v1.

Riddle: A harvest sown and reaped on the same day In an unplowed field, Which increases without growing, Remains whole though it is eaten Within and without, Is useless and yet The staple of nations.
What is it? Answer: War. — by Anonymous v2.