By now, the reader should be well aware of the fact that discrepancies and contradictions existed in the Pentateuch’s various genealogies because many of them were doublets—similar genealogical lists from two once separate traditions that were brought together by a later editorial endeavor. We have already seen examples of this (#7-10, #20-21).
It should come as little surprise then that in P’s genealogical list Lot is presented as the son of Abraham’s brother Haran (Gen 11:27, 12:5), thus making him Abraham’s nephew. However, J mentions him as Abraham’s brother (Gen 13:8). Noteworthy as well is that Lot does not make it into the book of Chronicles’ genealogy. Why?
We might make an educated guess at what’s going on here as this tradition progresses by looking at how these textual traditions stack up chronologically:
The Yahwist, written c. 8th c. BC, presents Lot as Abraham’s brother.
The Priestly text, c. 6th-5th c. BC, presents Lot as Abraham’s nephew.
The Chronicler, c. 4th c. BC, omits Lot from the family genealogy all together!
It might be surmised that later traditions sought to distance the embarrassing incestuous Lot (Gen 19:30-38) from his brother Abraham by making him, first, his nephew (P), and then by outright suppressing him from the genealogical tree all together, as the author of Chronicles did!
This is just one of the ways in which examining the Bible’s different textual traditions—evidenced through its many contradictions—informs us about the Bible’s textual history, and how (and hopefully why) its various traditions and stories were modified, and even contradicted by later writers. Even still, at some later point in time these different, modified, and contradictory traditions were compiled together, authenticated as Scripture, and labeled as “the Book” by a later generation of readers who had their own agenda and reasons for doing so.