The English "harrow" originated from an ancient word meaning a rake. A harrow is an agricultural implement that uses either fixed, usually pointed, metal rods attached to a frame, or revolving disks (a disk harrow) to break up and smooth the soil. Harrows have been known from ancient times.
"12:29 And David gathered all the people together [see also David, Future King Of Israel], and went to Rabbah, and fought against it, and took it. 12:30 And he took their king's crown from off his head, the weight whereof was a talent of gold with the precious stones: and it was set on David's head. And he brought forth the spoil of the city in great abundance. 12:31 And he brought forth the people that were therein, and put them under saws, and under harrows of iron, and under axes of iron, and made them pass through the brickkiln: and thus did he unto all the cities of the children of Ammon. So David and all the people returned unto Jerusalem." (2 Samuel 12:29-31 KJV)
"Break up your fallow ground: for it is time to seek the LORD, till he come and rain righteousness upon you"
Until relatively recent times in human history, harrows were pulled only by domesticated beasts of burden, such as oxen or horses (and still are in "third world" countries). Wild animals, such as the "unicorn" (which means "one horn" e.g. the rhinoceros - see Unicorns) would not submit to such a use.
"39:9 Will the unicorn be willing to serve thee, or abide by thy crib? 39:10 Canst thou bind the unicorn with his band in the furrow? or will he harrow the valleys after thee? 39:11 Wilt thou trust him, because his strength is great? or wilt thou leave thy labour to him? 39:12 Wilt thou believe him, that he will bring home thy seed, and gather it into thy barn?" (Job 39:9-12 KJV)
Harrowing is an important preparation for crop planting. Without it, most crops would have difficulty becoming established, let alone producing a good harvest.
"28:23 Give ye ear, and hear my voice; hearken, and hear my speech. 28:24 Doth the plowman plow all day to sow? doth he open and break the clods of his ground? 28:25 When he hath made plain the face thereof, doth he not cast abroad the fitches, and scatter the cummin, and cast in the principal wheat and the appointed barley and the rie in their place? 28:26 For his God doth instruct him to discretion, and doth teach him." (Isaiah 28:23-26 KJV)
Harrowing away roughness and clods is also used as an analogy for the producing of Good Fruit by a Christian.
"10:12 Sow to yourselves in righteousness, reap in mercy; break up your fallow ground: for it is time to seek the LORD, till he come and rain righteousness upon you." (Hosea 10:12 KJV)
John the Baptist (see The Elijahs) "harrowed" in preparation for the LORD's harvest of salvation when "the rough ways shall be made smooth."
"3:4 As it is written in the book of the words of Esaias the prophet, saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight. 3:5 Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth; 3:6 And all flesh shall see the salvation of God." (Luke 3:4-6 KJV)
Fact Finder: (a) How is the salvation of humanity like a harvest? (b) Why are some "weeds" permitted to grow in God's crop?