Leviticus 19:16-18

16You must not speak bad words about other people. If somebody is in danger of death, do not keep quiet if you know the truth. I am the Lord.

17You must not think bad thoughts about another person. A person may do something that is wrong. You must tell him that he is doing a wrong thing. If you do, you will not be a part of the wrong thing.

18You must not try to punish a person who has done something wrong against you. You must not continue to hate a person like that. Instead, you must love other people as much you love yourself. I am the Lord.