(21) All those wonders.--Not the "three signs" of Exodus 3:3-9, but the "portents" or "wonders "which were to be done before Pharaoh, and which had been alluded to in Exodus 3:20. These were, in the counsel of God, already "put into Moses' hand," though their exact nature was as yet unknown to Moses himself.

I will harden his heart.--The hardening of Pharaoh's heart has been the subject of much controversy. It is ascribed to God in this place, and again in Exodus 7:3; Exodus 9:12; Exodus 10:1; Exodus 10:20; Exodus 10:27; Exodus 14:4; Exodus 14:8; to Pharaoh in Exodus 8:15; Exodus 8:32; and Exodus 9:34; to the action of the heart itself in Exodus 7:13; Exodus 7:22; Exodus 9:7; Exodus 9:35. It is conceivable that these may be simply three forms of speech, and that the actual operation was one and the same in every case. Or, three different modes of operation may be meant. It is in favour of the latter view, that each term has a period during which it is predominant. In the narrative of what happened, the action of the heart is itself predominant in the first period; that of Pharaoh on his heart in the second; that of God in the third. We may suppose that, at first, Pharaoh's nature was simply not impressed, and that then his heart is said to have "hardened itself," or "remained hard;" that after a while, he began to be impressed; but by an effort of his will controlled himself, and determined that he would not yield: thus "hardening his own heart;" finally, that after he had done this twice (Exodus 8:15; Exodus 8:32), God stepped in and "smote him with a spirit of blindness and infatuation," as a judgment upon him (Exodus 9:12), thus, finally, "hardening" him (comp. Romans 9:18). This divine action was repeated, on three subsequent occasions (Exodus 10:20; Exodus 10:27; Exodus 14:8), Pharaoh's time of probation being past, and God using him as a mere means of showing forth His glory. There is nothing in this contrary to the general teaching of the Scriptures, or to the Divine Perfection.

Verses 21-23. - And the Lord said, etc. Now that Moses had at last given up his own will and entered on the path of obedience, God comforted him with a fresh revelation,, and gave him fresh instructions as to what exactly he was to say to Pharaoh. The statements of ver. 21 are not new, being anticipated in Exodus 3:19-20; but the directions in vers. 22-23 are wholly new, and point to the greatest of all the miracles wrought in Egypt - the death of the firstborn. Verse 21. - All those wonders. The miracles wrought in Egypt are called nipheloth, "marvels," mophethim, "portents," and othoth, "signs." Mophethim, the word here used signifies something out of the ordinary course of nature, and corresponds to the Greek τέρατα and the Latin portenta. It is a different word from that used in Exodus 3:20. In "all these wonders" are included, not only the three signs of Exodus 4:3-9, but the whole series of miracles afterwards wrought in Egypt, and glanced at in Exodus 3:20. I will harden his heart. This expression, here used for the first time, and repeated so frequently in chs. 7-14, has given offence to many. Men, it is said, harden their own hearts against God; God does not actively interfere to harden the heart of anyone. And this is so far true, that a special interference of God on the occasion, involving a supernatural hardening of Pharaoh's heart, is not to be thought cf. But among the natural punishments which God has attached to sin, would seem to be the hardening of the entire nature of the man who sins. If men "do not like to retain God in their knowledge, God gives them up to a reprobate mind" (Romans 1:28); if they resist the Spirit, he "takes his holy Spirit from them" (Psalm 51:11); if they sin against light he withdraws the light; if they stifle their natural affections of kindness, compassion and the like, it is a law of his providence that those affections shall wither and decay. This seems to be the "hardening of the heart here intended - not an abnormal and miraculous interference with the soul of Pharaoh, but the natural effect upon his soul under God's moral government of those acts which he wilfully and wrongfully committed.

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.And the Lord said unto Moses,.... At the same time he appeared to him in Midian, and ordered him to go into Egypt, even before his departure thither:

when thou goest to return into Egypt; and when got thither; for before the thing directed to in the next clause could not be done:

see that thou do all these wonders before Pharaoh which I have put in thine hand; not the three signs or wonders, related in the preceding part of the chapter, for they were to be done not before Pharaoh, but before the children of Israel; but these are the wonders he was to do in the sight of Pharaoh, by inflicting the various plagues on him and his people, for refusing to let Israel go, and which God had put in the power of Moses to perform, and that by means of the rod in his hand he ordered him to take with him, Exodus 4:17,

but I will harden his heart, that he shall not let the people go; that is, not directly, not for some time, not until all the wonders are wrought, and plagues inflicted to bring him to it: he first hardening his own heart against God, and all remonstrances made unto him, it was but a righteous thing in God to give him up to the hardness of his heart, to deny him his grace, which only could soften it, and to leave him to the corruptions of his nature, and the temptations of Satan; and by leaving him to strong delusions, to believe the lying miracles of his magicians: this the Lord thought fit to acquaint Moses with, lest he should be discouraged by his refusal to dismiss Israel.