לֹא־תֹאבֶ֣ה ל֔וֹ וְלֹ֥א תִשְׁמַ֖ע אֵלָ֑יו וְלֹא־תָח֤וֹס עֵֽינְךָ֙ עָלָ֔יו וְלֹֽא־תַחְמֹ֥ל וְלֹֽא־תְכַסֶּ֖ה עָלָֽיו׃
thou shalt not consent unto him, nor hearken unto him; neither shall thine eye pity him, neither shalt thou spare, neither shalt thou conceal him;
Sifrei Devarim
(Devarim 13:9) "You shall feel no affection for him": Because it is written (Vayikra 19:12) "And you shall love your neighbor as yourself," I might think that you shall love this one (the inciter), too; it is, therefore, written "You shall feel no affection for him."