Charles Ellicott Commentary Exodus 4:19

"And Jehovah said unto Moses in Midian, Go, return into Egypt; for all the men are dead that sought thy life." — Exodus 4:19 (ASV)

In Midian. —Moses appears to have delayed his departure after he obtained permission to go from Jethro. Therefore, the address “Go, return,” which is peremptory.

All the men who sought your life. —Not only the Pharaoh (Exodus 2:23), but the relatives of the murdered man, and the officials empowered by the Pharaoh to arrest Moses. As forty years had elapsed since the homicide, this is readily conceivable.