Exodus 4:21

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.