What Happens When You Don't Speak the Right Way?

Rashi: Since the skin affliction comes due to la chon hara, ill speech, therefore one needs birds for purification. Constantly chatter in a chirping voice away. The point is, you bring the birds cause you don't want to be like those birds. They're a reminder of what not to do. It means that essentially the message here is, speech itself is the problem. That's the lesson that needs to be eternalized.