Whether he is Oppressed or an Oppressor

Anas (RadiAllaahu Anhu) reported: Messenger of Allaah (Salallahu alaihe wa sallam) said, " Help your brother, whether he is an oppressor or is oppressed." A man inquired: "O Messenger of Allaah! I help him when he is oppressed, but how can I help him when he is an oppressor?" He (Salallahu alaihe wa sallam) said, "You can keep him from committing oppression. That will be your help to him." [Al-Bukhari]