דברי הימים א, פרק כ״ז, פסוק י״ח

During the organization of the national leadership, a man named Elihu from the brothers of David is appointed to lead the prominent tribe of Judah. However, a mystery surrounds his identity, as his name is completely absent from all other known records of David's family.

To resolve this historical puzzle, commentators offer a few explanations. The primary approach among commentators is that Elihu is simply another name for Eliab, David's oldest brother, meaning he carried two distinct names during his lifetime [רלב״ג, רד״ק, ביאור שטיינזלץ]. Alternatively, family titles were sometimes fluid, and the term for brothers might be used in a broader sense. In this view, Elihu was actually the son of one of David's brothers rather than a direct sibling [רלב״ג]. Another perspective proposes that Elihu was indeed a brother of David, but one who was simply left out of the earlier genealogical records [רד״ק].

Beyond the mystery of his exact placement in the family tree, a tragic historical tradition sheds light on his unique status. According to this account, Elihu was the sole remaining survivor of David's brothers. All the other siblings had previously lost their lives at the hands of the king of Moab, leaving Elihu alone to carry the family mantle and lead the tribe of Judah [מצודת דוד].