I am not sure if this topic is still being watched, but I really like Hebrew history. The ephod was a type of apron worn by the Jewish high priest. It's fascinating to look at.
The prophets were the shepherds of the nation of Israel and the shepherd's staff is used to guide the sheep in the direction of green pastures and water. The prophet's staff then, I believe, can be taken as an instrument of this symbolism...by extension.
In Psalm 23 we read, Thy rod and Thy staff, they comfort me. You lead me into green pastures and by the still waters.
The rod is, I believe, the nudging, prodding use of the staff...sometimes a bit harsher means...to bring the fold into line when being led, whereas the staff is the leading tool pointing the way of sorts.