Then the LORD said to Moses, “Rise up early in the morning and present yourself before Pharaoh and say to him, ‘Thus says the LORD, the God of the Hebrews, “Let my people go, that they may serve me.
13. And the Lord said unto Moses, Rise up. God returns again to threats, to try the mind of the wicked king; not that there is any hope of a cure, but that his obstinacy may be more and more discovered.
Here is, I. A general declaration of the wrath of God against Pharaoh for his obstinacy. Though God has hardened his heart (Exo 9:12), yet Moses must repeat his applications to him; God suspends his grace and yet demands obedience, to punish him for requiring bricks of the children of Israel when he denied them straw.
Commenting on Exodus 9:13-21
And the Lord said unto Moses, rise up early in the morning, and stand before Pharaoh,.... Who it seems used to rise early in the morning, and so was a fit time to meet with him, and converse with him; it might be one of the mornings in which he used to go to the water early, though not mentioned, unless that was every morning...