Here is one of the most extraordinary expansions in all of Targum Pseudo-Jonathan. The biblical Hebrew says only that Moses took the rod of God in his hand. The Aramaic adds a cosmic backstory: the rod was from the sapphire Throne of glory, in weight forty sein; and upon it was engraven and set forth the Great and Glorious Name.
Forty sein is an enormous weight — roughly hundreds of pounds. The rod is not a walking stick. It is a cosmic artifact. Carved from the sapphire Throne of Glory, the same material described in Exodus 24:10 beneath the feet of God, and engraved with the Shem ha-Meforash — the Explicit, Unpronounceable Name.
A Rod Passed Through the Generations
Later midrash (Pirkei de-Rabbi Eliezer 40) traces the rod's genealogy: created at twilight on the sixth day of creation, given to Adam in Eden, passed down through the generations to Noah, Shem, Abraham, Isaac, Jacob, Joseph, and finally confiscated by Pharaoh upon Joseph's death. Jethro took it from Pharaoh's courtyard and planted it in his garden, where no one could uproot it — until Moses came and pulled it out with ease.
That is why the Targum says Moses brought (it) away from the chamber of his father-in-law. The rod was waiting for him. Jethro's test had been its keeper.
The takeaway: the staff that will split the sea and strike the Nile is not a prop from Moses' shepherding days. It is the instrument of every patriarchal covenant, inscribed with the Name that holds creation together. When Moses lifts it, he lifts the accumulated weight of every promise ever made to Israel.