What does Genesis 25:13 mean?
The twelve sons of Ishmael are listed by order of birth in this and the following verses. The Lord had promised to Hagar that Ishmael would father "twelve princes," implying that each would become the head of his own clan or tribe (Genesis 17:20). Indeed, several peoples carrying the names of Ishmael's descendants become well known in the Middle East and in Israel's history.Ishmael's firstborn son Nebaioth becomes the representative of the family. Isaac's son Esau will later marry "Nebaioth's sisters," and Ishmael's daughters, Mahalath and/or Basemath (Genesis 28:9; 36:3). It's unclear if these are two women or one woman given two names.
Along with Nebaioth, Kedar became the name of a powerful Arab tribe. The descendants of Adbeel and Mibsam may have become lesser tribes in the region.