The ancient interpreters of Korah's rebellion (Numbers 16-17) include narrative expansions and other explanations in their retellings of the biblical narrative. Six Jewish and Christian interpretations are analyzed to determine on what basis the interpretations were made: LXX Numbers 16-17, Targum Pseudo-Jonathan Numbers 16-17, Josephus' Jewish Antiquities 4.11-66, Pseudo-Philo's Liber Antiquitatum Biblicarum 16-17, Origen's Homily 9 on Numbers, and Ambrose's Epistle to the Church at Vercellae.

Various bases of narrative expansions and explanations have been identified in the ancient interpretations by James L. Kugel, Bruce N. Fisk, and Jacob Neusner. These bases include: 1) details in the primary narrative, 2) secondary biblical references, 3) bases outside of Scripture (historical events, ideological concerns and extrabiblical writings), and 4) the imagination of the writer.

In the ancient interpretations of Korah's rebellion, examples from all of these categories are observed. In the ancient interpretations of Korah's rebellion, the most common basis is the primary narrative itself, in which details of the narrative suggest the addition or explanation to the interpreter. Almost as common are secondary biblical narratives. When the interpreters were unable to answer exegetical questions based on the primary narrative itself, they often turned to other biblical passages in the larger narrative context or passages with similar themes. Bases outside of Scripture, including the ideological concerns of the writer, are present in all of the interpretations studied, but are not the most significant basis for any of the interpretations. Finally, the imagination of the writer, with no other observable basis, is rarely the source of an interpretation observed in this study. The results of this study support the contention that the ancient interpreters, although influenced by their own ideology to a certain extent, were careful exegetes of the Scripture, who looked both to the details of the primary narrative and to related passages in the rest of the Bible in order to explain the narrative in front of them.