Thanks for the info, Keiva.
and I'll add, with more speculation than authority:
the slightly redundant nature of the original, translated as "rod and staff," is perhaps another manifestation of the redundancies which permeate the old testament, especially the pentateuch. According to Who Wrote the Bible?, Richard Friedman, there were four identifiable authors: one from Judah (J), one competitor from Israel (E), one later Aaronid priest (P), and one competing priest (D), who wrote separate works documenting the histories of the Jewish people from their own perspectives. The pentateuch was then consolidated into a single document which attempted to include the terms as used in all the various works, which is why the Bible is full of conflicts and redundancies.
It would be a bit like having had somebody from the US and somebody from England each write the story of the Revolutionary War in 1800, and then two others from the US and England write some updates in 1900, and then a fifth person putting the four documents together in 2000.
