And the Lord said unto Moses
Not at this time when he went out from Pharaoh, but some time before this, for the words may be rendered, "the Lord had said" F24, for so he had, as is related, ( Exodus 7:3 Exodus 7:4 ) , but the historian makes mention of it here, to show that Moses was not ignorant of the event of things; he knew that Pharaoh's heart would be hardened from time to time, and that one plague after another must be inflicted, before he would let the people go; and therefore when he prayed for the removal of any, it was not in expectation that he would abide by his promise, but to do the will of God, and the duty of his calling: Pharaoh shall not hearken unto you;
to Moses and Aaron, and let the people of Israel go as required of him: that my wonders may be multiplied in the land of Egypt;
which Jarchi interprets of the smiting of the firstborn, dividing the waters of the Red sea, and the destruction of Pharaoh and his host in it; but since these words were said before any of the plagues, were inflicted, it may refer to them all.
F24 (rmayw) "dixerat autem", Junius & Tremellius, Piscator, Rivet.