When someone gossips about you, the negativity they create transfers to their own soul, not yours. Stay calm, don't react, and send them positive energy instead. The universe will protect your reputation and they'll learn their own lessons.
Anytime someone is speaking badly about you, they're gossiping about you, you are part of their conversations, as long as you do not react, as long as you maintain certainty, as long as you not only judge them but you bless them, what is happening is negativity is being transferred from your soul, from parts of you that were blocked, and is actually going to their soul. So if you want to teach someone a lesson, if you want them to learn not to speak badly about you, the best thing to do is to pause, is to say thank you to the universe, and to send light and energy to the person that is speaking badly about you. Do not worry. The universe will protect your reputation. And if there are lessons that you must learn, you will learn them. No one can take what is yours. So we should never be afraid when someone is speaking badly about us.
