Do not wait in ambush.
We should not look to take revenge on others waiting for the best time to hurt them.
The mind of anger has one wish: to inflict harm. Sometimes we justify this harm on the grounds of “getting back” at the other person, other times we justify it as “deterring them” from inflicting harm on you again because they know you will strike back. But this is completely wrong. All we really do is guarantee that one day, when the opportunity presents itself, they will take advantage of our weakness and strike back.
There is another way. All bullies are the same: they threaten if you don’t do what I want, then I will do X to you. Because we don’t want X to happen to us, we go along with what the bully wants. But this just keeps us forever hostage to their demands. Instead, we do what is right, and let the pieces fall where they may. If the other person inflicts some penalty on us for doing what is right, then so be it. We accept this, but we do not change. This is actually an act of great compassion. If we allow others to manipulate us, they create terrible karma for themselves. If we show that they have no power over us, they will eventually give up trying. Thus, we protect them from creating such negative karma.