LEV570 We are forbidden to hate a fellow Jew. The Talmud (Erchin 16b) and Sifra state that this verse refers only to concealed hatred, for that is the most dangerous. If someone explicitly tells another person that he hates him, although he does not violate this prohibition, he does violate the commandment of "Love your fellow man." (Chinuch 237). A person should not think that only a violent feeling of animosity is prohibited, but a slight feeling of dislike is permitted. The Torah defines hatred in terms of the relation to a brother. Any lack of the feeling of brotherly love constitutes hatred. (Ohr Hachayim, on this verse). The Chofetz Chayim writes even if someone does not say or do anything against another person, but merely refuses to talk to him, he violates the prohibition against hating others. Moreover, for every second that one feels hatred toward another person, one violates this prohibition. (Ahavas Yisroel, ch. 2 and 4). The only way to repent for hating someone is by completely uprooting the feelings of hatred from your heart. (Ahavas Yisrael, ch. 5).