וְהָ֘שֵׁ֤ב לִשְׁכֵנֵ֣ינוּ שִׁ֭בְעָתַיִם אֶל־חֵיקָ֑ם חֶרְפָּ֘תָ֤ם אֲשֶׁ֖ר חֵרְפ֣וּךָ אֲדֹנָֽי׃
And render unto our neighbours sevenfold into their bosom Their reproach, wherewith they have reproached Thee, O Lord.
Read halakhic rulings (Jewish law) on Psalms 79:12: and classical halakhic sources.