And the Lord said. unto Moses Some connect this sentence with what follows, as if God had spoken to his servant after permission to return had been given him by his father-in-law; but my opinion rather is, that what had before been omitted is here inserted out of its place. Such repetition is frequent in the Scriptures. [1] Moses, therefore, adds to what he had already said, that the fear of danger was removed, since God had testified that the recollection of his having slain the Egyptian had ceased. For this would have been a stumblingblock at the very outset, if Moses had supposed that this accusation would have met him; not because his conscience smote him before God, but because he would have been rejected by the perverse judgments of men. Therefore, on this point, also, God provides against his fear, assuring him that the enemies were dead who had plotted against his life. And, perhaps, he now particularly notices this, because in asking for leave to depart, he could safely speak of it; for it is probable that Jethro, before he had married his daughter to an unknown foreigner, had demanded the cause of his exile; since it was easy to conjecture by his wandering in the Desert, that he had been expelled from his country. Having then confessed that he fled from the wrath of the king, he now says that he is recalled by divine revelation, and that a safe return is promised him. Nor is he guilty of falsehood; for, amongst other things, God had promised him that no danger awaited him from his former enemies.

Footnotes

1 - "And the Lord said unto Moses in Midian, i e., at a different time from that when he appeared to him in the wilderness at Mount Sinai. Things are not always recorded in the sacred writings in the order in which they happened." -- Rosenmuller in loco

In Midian - This was a new revelation, and appears to have taken place after Moses returned to his father-in-law previous to his departure for Egypt.

And the Lord said unto Moses in Midian,.... 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 backwardness to go into Egypt, and which was now removed.

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.

Return of Moses to Egypt. - Exodus 4:19-23. On leaving Midian, Moses received another communication from God with reference to his mission to Pharaoh. The word of Jehovah, in Exodus 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 Exodus 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 encouraged him to return, by informing him that all the men who had sought his life, i.e., Pharaoh and the relatives of the Egyptian whom he had slain, were now dead.

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.