Romans 9:17 - Wesley's Explanatory Notes

Moreover — God has an indisputable right to reject those who will not accept the blessings on his own terms. And this he exercised in the case of Pharaoh; to whom, after many instances of stubbornness and rebellion, he said, as it is recorded in scripture, For this very thing have I raised thee up — That is, Unless thou repent, this will surely be the consequence of my raising thee up, making thee a great and glorious king, that my power will be shown upon thee, (as indeed it was, by overwhelming him and his army in the sea,) and my name declared through all the earth — As it is at this day. Perhaps this may have a still farther meaning. It seems that God was resolved to show his power over the river, the insects, other animals, (with the natural causes of their health, diseases, life, and death,) over the meteors, the air, the sun, (all of which were worshipped by the Egyptians, from whom other nations learned their idolatry,) and at once over all their gods, by that terrible stroke of slaying all their priests, and their choicest victims, the firstborn of man and beast; and all this with a design, not only to deliver his people Israel, (for which a single act of omnipotence would have sufficed,) but to convince the Egyptians, that the objects of their worship were but the creatures of Jehovah, and entirely in his power, and to draw them and the neighbouring nations, who should hear of all these wonders, from their idolatry, to worship the one God. For the execution of this design, (in order to the display of the divine power over the various objects of their worship, in variety of wonderful acts, which were at the same time just punishments for their cruel oppression of the Israelites,) God was pleased to raise to the throne of an absolute monarchy, a man, not whom he had made wicked on purpose, but whom he found so, the proudest, the most daring and obstinate of all the Egyptian princes; and who, being incorrigible, well deserved to be set up in that situation, where the divine judgments fell the heaviest. Exodus 9:16.