וְהָלַכְתִּ֥י עִמָּכֶ֖ם בַּחֲמַת־קֶ֑רִי וְיִסַּרְתִּ֤י אֶתְכֶם֙ אַף־אָ֔נִי שֶׁ֖בַע עַל־חַטֹּאתֵיכֶם׃
then I will walk contrary unto you in fury; and I also will chastise you seven times for your sins.
Read midrashic interpretation of Leviticus 26:28: and classical rabbinic exegesis.