The chapter names Isaac and Ishmael as Abraham’s sons and also lists sons of Keturah (1 Chronicles 1:28–33). These names show related family lines alongside Israel’s main line through Isaac (1 Chronicles 1:28–33).
In 1 Chronicles 1:28–33, the writer lists Abraham’s sons and then traces lines that come through Ishmael and through Keturah. Isaac and Ishmael are named first, then Ishmael’s “generations” are given as a sequence of twelve sons. This passage sits inside the opening genealogies of 1 Chronicles, where the writer moves from broad humanity toward Israel’s story and its surrounding family lines. The method is list-like and selective: names are grouped under key ancestors, then narrowed to sub-branches, then summarized before moving on.
This unit treats Abraham as a branching point for multiple family lines, not only the line that leads to Israel through Isaac. It names Isaac and Ishmael as Abraham’s sons (verse 28), then gives a structured list of Ishmael’s descendants (verses 29–31), and then a list of descendants through Keturah (verses 32–33).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with 1 Chronicles 1:28-33, then read the surrounding section so the answer stays connected to the passage's flow.
28The sons of Abraham: Isaac, and Ishmael.
29These are their generations: the firstborn of Ishmael, Nebaioth; then Kedar, and Adbeel, and Mibsam,
30Mishma, and Dumah, Massa, Hadad, and Tema,
31Jetur, Naphish, and Kedemah. These are the sons of Ishmael.
32The sons of Keturah, Abraham`s concubine: she bore Zimran, and Jokshan, and Medan, and Midian, and Ishbak, and Shuah. The sons of Jokshan: Sheba, and Dedan.
33The sons of Midian: Ephah, and Epher, and Hanoch, and Abida, and Eldaah. All these were the sons of Keturah.