Midrash sobre Génesis 4:20

"And Enoch begat Erad..." Rabbi Yehoshua ben Levi said: They all refer to rebellion. Erad - I will drive him out from the world. Mechuya'el - I will erase him from the world. Metusha'el - I will weaken him from the world. Lemech - What do I need with Lemech and his descendents? "And Lemech took for himself two wives, one was named Adah and the second was named Tzilah" (Genesis 4:19). Rabbi Azariah said in the name of Rabbi Yehudah bar Simon: this is what the men of the generation of the Flood would do: each of them would take two wives, one for procreation and one for pleasure. The one who was for procreation would sit as if she was a widow in her own lifetime (in the lifetime of her husband), and the one that was for pleasure would drink a cup for sterility so that she did not bear [children], and would sit by him adorned like a prostitute. As it is written: "He devours the barren that do not conceive, and does not do good to the widow" (Job 24:21). Know that among them the best was Lemech, and he took two wives, as it says "And Lemech took for himself two wives, one was named Adah" - because she became pregnant [adah] "and the second was named Tzilah" - because she sat in his shade [tzel].

..."Tubal-Cain": R. Yehoshua of Sakhnin said in the name of R. Levi, "This one sweetened (literally, spiced) Cain's sin (some have the variant, 'Cain's work') - Cain would kill, but he did not have with what to kill; but this one 'forged every cutting instrument of copper and iron.'" And the sister of Tubal-Cain was Na’amah. Rabbi Abba bar Kahana said: Na’amah was Noah’s wife. Why was she called Na’amah? Because all of her deeds were pleasant (ne’imim). The Rabbis said this is a different Na’amah. Why was she called Na’amah? Because she beat on a drum to draw people to idol worship.