Most Relevant Verses
At that time the LORD said to Joshua, "Make for yourself flint knives and circumcise again the sons of Israel the second time." So Joshua made himself flint knives and circumcised the sons of Israel at Gibeath-haaraloth.
More Verses on Sharpness
For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart.
For this reason I am writing these things while absent, so that when present I need not use severity, in accordance with the authority which the Lord gave me for building up and not for tearing down.
Then I looked, and behold, a white cloud, and sitting on the cloud was one like a son of man, having a golden crown on His head and a sharp sickle in His hand. And another angel came out of the temple, crying out with a loud voice to Him who sat on the cloud, "Put in your sickle and reap, for the hour to reap has come, because the harvest of the earth is ripe." Then He who sat on the cloud swung His sickle over the earth, and the earth was reaped. read more.
And another angel came out of the temple which is in heaven, and he also had a sharp sickle. Then another angel, the one who has power over fire, came out from the altar; and he called with a loud voice to him who had the sharp sickle, saying, "Put in your sharp sickle and gather the clusters from the vine of the earth, because her grapes are ripe."