Nahum 3:1-19, Psalm 73:17-19
In Chapter 2, it was revealed that God would bring destruction upon the Assyrians, and He did. The Assyrians had led God's children astray, and so they were punished. This principle holds true today as well. If anyone tries to harm one of God's children, He will seek vengeance on their behalf at the right time and in the right way. No sin goes unpunished.
If someone is spreading lies about you, it's important to remember that God sees everything and will take action when the time is right. It is our duty to pray for our enemies and forgive them, but we should not take matters into our own hands. Ultimately, it is God who will be the judge.