Exodus 4:19

“And the Lord said unto Moses in Midian, etc.] After he had obtained leave of his father-in-law to quit Midian, but before he left it; go, return into Egypt: that is, directly, immediately; before he had only given him a commission at large to go thither, but had not fixed the time when he should go; but now he orders him to set forward at once: for all the men are dead which sought thy life; to take it away, the king of Egypt, and his ministers, and the friends of the Egyptian Moses had slain; and this is said to encourage him to go; and though Moses had never expressed his fear on this account, or made it an objection, yet it might lie secretly in his heart, and be one reason of his…”

“all the men are dead which sought thy life--The death of the Egyptian monarch took place in the four hundred and twenty-ninth year of the Hebrew sojourn in that land, and that event, according to the law of Egypt, took off his proscription of Moses, if it had been publicly issued.”

“The Lord said unto Moses - This seems to have been a second vision, whereby God calls him to the present execution of the command given before. Exodus 4:20”

“Midian: A country in Arabia Petrea, on the eastern coast of the Red Sea, near Mount Sinai. This place is still called by the Arabs the Land of Midian, or of Jethro. Abulfeda, speaking of Midian, says, "Madyan is a city, in ruins, on the shore of the Red Sea, on the opposite side to Tabuc, from which it is distant about six days' journey. At Midian may be seen the famous well at which Moses watered the flocks of Shoaib (Jethro). This city was the capital of the tribe of Midian in the days of the Israelites." for all: Exo 2:15, Exo 2:23; Mat 2:20 Exodus 4:20”

“Return of Moses to Egypt. - Exo 4:19-23. On leaving Midian, Moses received another communication from God with reference to his mission to Pharaoh. The word of Jehovah, in Exo 4:19, is not to be regarded as a summary of the previous revelation, in which case ויּאמר would be a pluperfect, nor as the account of another writer, who placed the summons to return to Egypt not in Sinai but in Midian. It is not a fact that the departure of Moses is given in Exo 4:18; all that is stated there is, that Jethro consented to Moses' decision to return to Egypt. It was not till after this consent that Moses was able to prepare for the journey. During these preparations God appeared to him in Midian, and…”