Basemath (also known as Bashemath) was a daughter of Ishmael and wife of Esau, son of Isaac. She is mentioned in the genealogies in Genesis as one of Esau's Canaanite and Ishmaelite wives, and became the mother of Reuel. Her marriage represented a connection between the family lines of Esau and Ishmael.
Esau saw that his Canaanite wives displeased his father Isaac, so he took Bashemath (Basmat), the daughter of Ishmael and sister of Nebajoth, as a wife.
17These were the sons of Esau's son Reuel: Chief Nahath, Chief Zerah, Chief Shammah, Chief Mizzah. These were the chiefs descended from Reuel in the land of Edom; they were the descendants of Esau's wife Basemath.
2Esau took his wives from the daughters of Canaan: Adah daughter of Elon the Hittite, and Oholibamah daughter of Anah, granddaughter of Zibeon the Hivite,[^1]
[^1]: The Hebrew reads "daughter of Zibeon"; according to verses 24–25 Zibeon was Anah's father, so "granddaughter" is intended.
The marriage between Esau and Bashemath, Ishmael's daughter, created an important family connection between two branches of Abraham's family that were both outside the covenant line through Isaac and Jacob.
6Esau saw that Isaac had blessed Jacob and sent him to Paddan-aram to take a wife from there, and that when he blessed him he charged him, "Do not take a wife from the daughters of Canaan,"