Y’honatan spoke well of David to Sha’ul his father and said to him, “The king shouldn’t sin against his servant David, because he hasn’t sinned against you. On the contrary, his work for you has been very good indeed.
This isn’t license for taking revenge. This is sage advice. Even if you dislike someone, if they haven’t done anything wrong to you, you definitely should not wrong them. This is simple wisdom, but that doesn’t mean it is easy to follow. It is easy to hate others casually and see them as less than. Guard yourself that you don’t make enemies through carelessness.