Charles Ellicott Commentary Exodus 4:18

"And Moses went and returned to Jethro his father-in-law, and said unto him, Let me go, I pray thee, and return unto my brethren that are in Egypt, and see whether they be yet alive. And Jethro said to Moses, Go in peace." — Exodus 4:18 (ASV)

Moses ... returned to Jethro. —Hebrew, to Jether. When Moses married Zipporah, he was probably adopted into the tribe, of which Reuel, and after him Jethro, was the head. The tribal tie was close, and would make asking permission for even a temporary absence the proper, if not even the necessary, course. Apart from this, Moses would have had to “return,” in order to restore the flock, which he was tending, to its owner.

My brethren. —Not “my nation,” for Moses could not doubt that some survived; nor “my actual brothers,” for he had but one brother; but, “my relations,” or “my family,” my kith and kin. Let me go and see whether my relatives survive, or whether they have succumbed to the tyranny of the Pharaoh. It is certain that this was not Moses’ sole motive, not even his main motive for wishing to return to Egypt; but, as it was among his motives, he was within his right in putting it forward, and omitting to mention others.

Jethro said, Go in peace. —Jethro’s character is altogether one in which kindness and peacefulness are the main elements. If he is identified with Reuel, the pleasing picture drawn in Exodus 2:18-21 will furnish traits for his portraiture. Even without this, the present passage and the notice in Exodus 18:0 sufficiently delineate him. He is a sort of second Melchizedek, both priest and king, a worshipper of the true God, and one in whose presence both Moses and Aaron are content to play a secondary part (Exodus 18:9; Exodus 18:12). But he never asserts himself; he is always kind, gentle, acquiescent, helpful.

He might easily have raised an objection at this point in the narrative, demurred to the weakening of the tribe by the withdrawal of an important member from it, or positively refused to allow the departure of Zipporah and her children. But his words are simply Go in peace. He consents, and does not mar the grace of his act by any show of reluctance. He lets Moses take his wife and children. He afterwards receives them back and protects them (Exodus 18:2); and, finally, when his protection is no longer needed, he restores them to their natural guardian, by a spontaneous act, as it would seem.