Many years ago I had a pair of kitchen scissors which could cut larger pieces of chicken bone into mouth sized chunks, as often used in Asia for curries. The blades were not lethal to touch but if applied with force that was a different matter in its effect on bone. Similarly, one seemingly innocent word or two can also be used to cause great damage. The Message translation of Proverbs 18:21 says it very succinctly: "Words kill, words give life; they're either poison or fruit - you choose."