LEV555 It is a negative commandment not to hate in one's heart any decent person in Jewry as Scripture says, You shall not hate your brother in your heart [this verse]. And should one man sin against another, he should not bear hatred for him in his heart and keep silent. Instead, it is a religious duty for him to inform the other person and tell him, "Why did you do thus–and–so to me?" And he should erase the hatred from his heart. If, however, he saw the other person committing a sin, whereupon he warned him, but the other did not turn back, it is then a religious duty for him to hate the other one (since he does not conduct himself as "your brother").