Zanti message and Lisa in “Unfinished Business”

This is the commander of the government of the planet Zanti. I speak to you from Zanti. You have destroyed the mistakes. We will not retaliate. We never intended to. We knew that you could not live with such aliens in your midst. It was always our intention that you destroy them, and their guards, who were of the same spoiled persuasion. We chose your planet for that purpose. We are incapable of executing our own species, but you are not. You are practiced executioners. We thank you.

[dryly] "Practiced executioners".