Answer:
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.
I do not breathe, but I run and jump. I do not eat, but I swim and stretch. I do not drink, but I sleep and stand. I do not think, but I grow and play. I do not see, but you see me everyday.
What goes in, but never through? I've got some and so do you. We might lend one, or even two, but only if our trust is true.
My life is often a volume of grief, your help is needed to turn a new leaf. Stiff is my spine and my body is pale. But I'm always ready to tell a tale.
I have a face, yet no senses. But I don't really care, because time is of the essence.
I repeat only the last word you say. The more I repeat, the softer I got. I cannot be seen but can be heard. What am I?