Exodus 3:18

They shall hearken. Moses thought that they would despise him, turn a deaf ear to his words, and reject his leadership. But God told him that his reception this time would differ greatly from the one he had received 40 years before. The hearts of men are in God’s hands, and God Himself had directed the affairs of His people in such a way that they would be ready to recognize Moses as God’s chosen instrument for their deliverance.

Now let us go. The request for Pharaoh’s permission to leave the country is phrased so as to express Israel’s precise relation to him. He had no right to detain them, but his consent was needed for their departure as was that of a former king for their settlement in the land of Goshen (Gen. 45:16-20). He had no valid reason for refusing their request to go three days’ journey into the wilderness, for their return at the close of that period was implied in the request. Was this deception? By no means. God knew the heart of Pharaoh and instructed Moses to ask no more at first than he must either grant, or, by refusing, display the hardness of his heart. Had Pharaoh consented, God would probably then have made known to him His design in its entirety and demanded the permanent release of His people. When Pharaoh refused the first, and reasonable, request (Ex. 5:2), Moses was to demonstrate the power of the God of the Hebrews by miracles and judgments. Accordingly, Moses persisted in demanding permission for the people to go and serve their God (chs. 7:16; 8:1; 9:1, 13; 10:3). It was not until the king offered to permit them to sacrifice in Egypt that Moses added to his request the significant phrase, “as he shall command us” (ch. 8:27), which implied that they might not return. Of course, that was what Pharaoh feared.