Jan WIm Wesselius , From stumbing blocks to cornerstones: The function of problematic episodes in the Primary History and in Ezra-Nehemiah, digital, [2006], 51, Moses' grandson
... 'And the Danites set up the
graven image for themselves; and Jonathan the son of Gershom, son
of Moses, and his sons were priests to the tribe of the Danites until the
day of the captivity of the land' (Judges 18:30). Of course, critical,
literary and fundamentalist scholars have an entire array of methods to
get around the embarrassing contradiction between this verse and the
description of history up to this point, but if we try to read the Primary
History as the unitary literary work as which it presents itself to us,
such options are not open to us. Moses' son Gershom has been
brought to our especial attention in a number of passages (Exodus
2:22 and 18:3, note also the 'bridegroom of blood' episode on Moses'
return from Midian to Egypt in Exodus 4:24-26). If we find here a
Levite, Jonathan son of Gershom, son of Moses, within such a closely
knit literary work, this can only serve as a direct reference; the letter
nun written in the Masoretic text above the line in the name of Moses,
which would make it into an otherwise unknown Manasseh,
complicates the situation but its addition does not really give a viable
alternative (see also below). ...