כִּ֤י לֹ֥א שָׁל֗וֹם יְדַ֫בֵּ֥רוּ וְעַ֥ל רִגְעֵי־אֶ֑רֶץ דִּבְרֵ֥י מִ֝רְמוֹת יַחֲשֹׁבֽוּן׃
For they speak not peace; But they devise deceitful matters against them that are quiet in the land.
Read halakhic rulings (Jewish law) on Psalms 35:20: and classical halakhic sources.