After the expulsion from Eden, Adam separated from Eve for 130 years. According to Eruvin 18b, during that long estrangement, he fathered an entirely different kind of offspring—demons.
Rabbi Yirmeya ben Elazar taught: during those 130 years, Adam produced spirits, demons (shedim, שדים), and liliths (female night spirits). The proof text is (Genesis 5:3): "And Adam lived 130 years and begot a son in his likeness, after his image." The implication is clear: before Seth, who was "in his likeness," the children Adam produced were not in his likeness. They were something else entirely.
The passage is embedded in a broader discussion about the creation of Eve. The Talmud in Eruvin 18b teaches that God served as Adam's best man, arranging the wedding and bringing Eve to him (Genesis 2:22). This detail establishes a principle: a greater individual should serve a lesser one without feeling diminished.
The Sages also debated Eve's original form. Some held that she was a separate face on Adam's body—they were created back to back, and God separated them. Others said she was a full side, not merely a rib. The word tzela (צלע) in Hebrew can mean either "rib" or "side."
Rav Nahman raised an awkward observation: Manoah, the father of Samson, is described as walking behind his wife (Judges 13:11)—which the Talmud considers improper. Does this make Manoah an ignoramus? The Talmud resolves it: "walking after" means following her counsel, not literally walking behind her. The same applies to Elkana following Hannah and Elisha following the Shunammite woman.
The 130 years of demon-fathering became a cornerstone of later Jewish demonology—the idea that the invisible population of harmful spirits traces its lineage directly to the first human being.