There is a tendency to treat the words “rod” and “staff” as being basically the same thing in the English language. A quick reference to an English language dictionary will reveal some ambiguity in that the word “rod” is used to explain “staff,” and the word “staff” is used to explain “rod.” All in all, there exists a considerable overlap in meaning.
It turns out that in Hebrew the distinctions are not as crisp as we would like for them to be either. Editorial groups disagree in translations. However, all seem to agree that a rod, or a staff for that matter, is a large, straight stick of some sort. For our purposes, I’ll go out on a limb here and try to make a distinction that will work for this discussion.
As has been said “rod” and “staff” are largely interchangeable. However, “rod” seems to be more closely related to a weapon or even an implement of discipline (e.g. Proverbs 13:24). The “staff” seems to be more related to an implement of support. As I implied, these are general guides only and there is a high degree of interchangeable use.
Another aspect of distinction is that “rod” is closer in meaning to “scepter” than is “staff.” Of course, we are aware that the word “scepter” refers to a visual symbol of authority. Again, though, the imprecision and inconsistency of usage is a bit frustrating.
One thing we can say is that “staff” is generally not used in association with discipline, while “rod” is. Because the use of a rod in discipline is so common, we will use that association. Furthermore, we will extend the use to symbols of rule or authority.