sons. Gershom and Eliezer. See on Exodus 2:1.
upon an ass. Still young, So that Moses married after many years in Midian.
rod of God. His own rod is now thus dignified.
Related Commentaries of Exodus 4:20
Exodus 4:20
20 And Moses took his wife and his sons, and set them upon an ass, and he returned to the land of Egypt: and Moses took the rod of God in his hand.