(The church website is down as I write this, so I won't have the usual links. I'm not going to come back and add them later, so you'll just have to look the verses up yourself.)
I mentioned in class and have written elsewhere that the Melchizedek priest bears a staff (see Psalms 110 and 23, as well as the "rod" of 1 Nephi 8, and elsewhere). The staff imagery in the Book of Exodus is really interesting.
When the Lord commissions Moses from the burning bush, He asks Moses "What's that in your hand?" and Moses says "A staff" (Exodus 4:2). Not my staff, just a staff. That's interesting, because it leaves open the possibility that the Lord has just given the staff to Moses. This possibility becomes an outright probability when we read Exodus 4:20 and 17:9, both of which call this same staff matteh haElohim. The KJV translates this as "the staff of God," but for grammatical reasons (the ha is the article "the," which is unnecessary in front of a singular name), a better reading is "the staff of the gods." The Lord gives Moses the staff of the Gods -- He confers on Moses the Melchizedek priesthood.
The appearance of this staff is especially interesting in Exodus 17. In a battle against Amalek, Moses' role is to stand on top of a hill (= temple?) holding the staff in his hands. There he sits on a Rock (enthroned like God on the Foundation Stone) with helpers (Cherubim) to his left and right. The image here is of the Lord going to war with his people enthroned on the Ark of the Covenant, as He does for instance in 1 Samuel 4. When he holds the staff of office, Moses is Melchizedek / the Lord.
Numerous passage connect this staff with serpents, suggesting maybe that it was a caduceus. See Exodus 4:3-4, 7:8-10; Numbers 21:49 (in connection with which, John 3:14 and 1 Nephi 17:41), and Isaiah 14:29 (in which a murdered (righteous) priest is equated with a broken staff, which is also a defeated serpent).