Was Shelah the son of Arphaxad or of Cainan?

Many who hold that Scripture is without error answer that this second Cainan was not in Luke’s original text but came in through an early copyist’s slip. A different Cainan, the son of Enos, stands a little further on in the same list (Luke 3:37), and in ancient copies, written in capitals without spaces, a scribe whose eye strayed to that line could write ‘of Cainan’ one place too soon. Every Hebrew text of Genesis 10:24, Genesis 11:12–13 and 1 Chronicles 1:18, 24 makes Salah the son of Arphaxad, as do the Samaritan Pentateuch, the Targums and Josephus, and so does the main Septuagint text of 1 Chronicles 1:24 (see textual). John Gill took this view in the eighteenth century; Answers in Genesis follows him, and Andrew Steinmann argued it at length in 2017.

On this reading Genesis and Luke, as first written, agree, and the extra name is a slip in the copying of Luke, not an error in the original.

The Septuagint’s Cainan

Luke usually follows the Greek Old Testament, the Septuagint, and the surviving Septuagint manuscripts of Genesis 10:24 and 11:12–13 include Cainan, with his own age at fatherhood. Some Christian scholars therefore hold that Luke is right and that the name dropped out of the Hebrew of Genesis; the surviving text of the book of Jubilees, written in the second century BC, also has a Cainan (Kainam) here. Gill, on the other hand, thought the name was added to the Septuagint later, from Luke.

A gap in Genesis

Others, such as Apologetics Press, note that biblical genealogies sometimes skip generations, so that ‘begat’ in Genesis 11:12 could mean ‘became the ancestor of’. The difficulty is that Genesis gives Arphaxad’s age at the birth, which makes a gap harder to fit here.

This is still debated. Christian scholars who hold to inerrancy divide between a copyist’s addition in Luke and a name lost from the Hebrew of Genesis, and the oldest evidence does not settle it either way.