כֹּ֣ה ׀ אָמַ֣ר יְהוָ֗ה מַה־מָּצְא֨וּ אֲבוֹתֵיכֶ֥ם בִּי֙ עָ֔וֶל כִּ֥י רָחֲק֖וּ מֵעָלָ֑י וַיֵּֽלְכ֛וּ אַחֲרֵ֥י הַהֶ֖בֶל וַיֶּהְבָּֽלוּ׃
永恆者如此說：«你們的列祖在我身上找到了甚麼不義，竟遠離我，去追隨虛無的偶像，自己也變得虛無？»
Shenei Luchot HaBerit
Midrash Kohelet, quoting Rabbi Yehudah bar Simon, is of the opinion that the seven days of impurity a woman experiences in connection with menstruation correspond to the seven times Solomon referred to הבלים, futilities, in Kohelet 1,2. [When the word הבל appears in the singular it refers to a single "futility," whereas when it appears in the plural it refers to two "futilities." Ed.] This means that in view of the sin committed by Adam and Eve everything which was created during the seven days of Creation is futile. Creation experienced another damaging blow when Cain murdered his brother הבל. Man indulged in the pursuit of futile objectives, וילכו אחרי ההבל ויהבלו, "They went after delusion and were deluded" (Jeremiah 2,5).