Painful as a sword

Sometimes tongue can be as painful as sword. Why? We can be tactless at times! For us, the words we are saying are just nothing and would mean nothing. But for the one, who hear it, seems it’s already hurting for them. And that they just keep it inside their heart. Hmmm, not good! So I if possible we will guard whatever words we will say. Though sometimes we can’t avoid being tactless.