'Harrow' in the Bible

Canst thou bind the unicorn with his band in the furrow? or will he harrow the valleys after thee?

Does the farmer plow continually to plant seed?Does he continually turn and harrow the ground?

And Ephraim is a trained heifer -- loving to thresh, And I -- I have passed over on the goodness of its neck, I cause one to ride Ephraim, Plough doth Judah, harrow for him doth Jacob.