Righteous people are thoughtful communicators — they study their words before speaking, considering the effect and truth of what they will say. The wicked have no such discipline; their mouths are a torrent of harmful words. This contrast reinforces the book's consistent theme: speech is a moral issue.
Memory phrase: Think before you answer.
Talk about it: Why is it wise to think before answering?
Prayer: God, help me think before I speak.