כִּ֣י צֹרְרִ֥ים הֵם֙ לָכֶ֔ם בְּנִכְלֵיהֶ֛ם אֲשֶׁר־נִכְּל֥וּ לָכֶ֖ם עַל־דְּבַר־פְּע֑וֹר וְעַל־דְּבַ֞ר כָּזְבִּ֨י בַת־נְשִׂ֤יא מִדְיָן֙ אֲחֹתָ֔ם הַמֻּכָּ֥ה בְיוֹם־הַמַּגֵּפָ֖ה עַל־דְּבַר־פְּעֽוֹר׃
for they harass you, by their wiles wherewith they have beguiled you in the matter of Peor, and in the matter of Cozbi, the daughter of the prince of Midian, their sister, who was slain on the day of the plague in the matter of Peor.’
Read kabbalistic (mystical) interpretation of Numbers 25:18: and classical mystical sources.