The Gemora in Shabbos 32B says in the name of R’ Nechemya that because of ‘Sinaas Chinom’ there are fights in a person’s home, his wife miscarries and his children die young. Rashi explains that ‘Sinaas Chinom’ means any hatred that is not generated through a sin committed by the hated. The Cofetz Chaim says that we may not hate even for a sin, because our intent is not pure. So any hatred we feel towards any Jew is included in ‘Sinaas Chinom’.
Hating another Jew