There is a saying which goes like this “Don’t answer quickly when you are nervous, postpone the reply”.
The basic idea is to think for a while, and postpone the answer, if you can forget about the hatred and despise, and don’t apply anger.
In an ideal world, you wouldn’t want revenge.
If it troubles you a lot, the fact that you are sitting and thinking, instead of answering – you only make things worse.
You have to set yourself for forgiveness if you want to do this: “I will not reply now, but tomorrow”.