4:18-23 After God had appeared in the bush, he often spake to Moses. Pharaoh had hardened his own heart against the groans and cries of the oppressed Israelites; and now God, in the way of righteous judgment, hardens his heart against the teaching of the miracles, and the terror of the plagues. But whether Pharaoh will hear, or whether he will forbear, Moses must tell him, Thus saith the Lord. He must demand a discharge for Israel, Let my son go; not only my servant, whom thou hast no right to detain, but my son. It is my son that serves me, and therefore must be spared, must be pleaded for. In case of refusal I will slay thy son, even thy first-born. As men deal with God's people, let them expect so to be dealt with.

20. Moses took his wife and his sons, and set them upon an ass—Septuagint, "asses." Those animals are not now used in the desert of Sinai except by the Arabs for short distances.

returned—entered on his journey towards Egypt.

he took the rod of God—so called from its being appropriated to His service, and because whatever miracles it might be employed in performing would be wrought not by its inherent properties, but by a divine power following on its use. (Compare Ac 3:12).