Exodus Chapter 10 Verses 1,2

:1 “And the LORD said unto Moses, Go in unto Pharaoh: for I have hardened his heart, and the heart of his servants, that I might show these my signs before him: 2 And that thou mayest tell in the ears of thy son, and of thy son's son, what things I have wrought in Egypt, and my signs which I have done among them; that ye may know how that I am the LORD.” 

“And the LORD said unto Moses, Go in unto Pharaoh: for I have hardened his heart, and the heart of his servants, that I might show these my signs before him:” The LORD hardened the hearts of Pharaoh and the heart of his servants.  The unregenerate heart is hardened by the commandment, challenge, and judgment of God.  The unregenerate does not want to believe in God and absolutely does not want to obey God and will resist in every way.  Pharaoh and his servants did not want to acknowledge there was a God and resisted in every way the commandments of God.   

Through hardening the heart of Pharaoh and his servants, God used the occasion of their rebellion to show forth his mighty signs not only before Pharaoh, but also in the sight of His people.  

“And that thou mayest tell in the ears of thy son, and of thy son's son, what things I have wrought in Egypt, and my signs which I have done among them; that ye may know how that I am the LORD.”  By seeing the mighty signs of God against Pharaoh and Egypt, the Israelites saw the mighty power of God and realized that God keeps his promises.  Further, God designed that those who saw these mighty signs would tell it to their children and their grandchildren.  This was very important that the children and grandchildren hear of the wonders of an Almighty God and of his faithfulness to his covenant promises.  By hearing these things, it encourages the children and the grandchildren in their life struggles to know that their parents and grandparents had many struggles themselves and that God according to his promises delivered them in the midst of their struggles.  Sometimes, we as parents and grandparents fail to tell our children and grandchildren of the mighty deliverances that God has delivered us with.  Then we wonder why our children and grandchildren do not have the same zeal for the Lord and want to follow him as we have.  Part of the problem may be that we are not sharing with our children and grandchildren the struggles of our own lives and how that by looking to the Lord and praying we have experienced the Lord’s deliverances in our lives.   

The LORD was teaching here that parents should share with their children and grandchildren their own experiences in the Lord and his providence towards us.   

Verses 3-6

:3 And Moses and Aaron came in unto Pharaoh, and said unto him, Thus saith the LORD God of the Hebrews, How long wilt thou refuse to humble thyself before me? let my people go, that they may serve me. 4 Else, if thou refuse to let my people go, behold, to morrow will I bring the locusts into thy coast: 5 And they shall cover the face of the earth, that one cannot be able to see the earth: and they shall eat the residue of that which is escaped, which remaineth unto you from the hail, and shall eat every tree which groweth for you out of the field: 6 And they shall fill thy houses, and the houses of all thy servants, and the houses of all the Egyptians; which neither thy fathers, nor thy fathers' fathers have seen, since the day that they were upon the earth unto this day. And he turned himself, and went out from Pharaoh.”  

“And Moses and Aaron came in unto Pharaoh, and said unto him, Thus saith the LORD God of the Hebrews, How long wilt thou refuse to humble thyself before me? let my people go, that they may serve me.”  Notice, how that before the LORD pronounced judgment upon Pharaoh and Egypt that he first told them what he wanted and commanded them to do.  This pattern holds throughout the scriptures.  It is commandment first then judgment.  God’s judgments are not random but befitting of the sin committed.  

“Else, if thou refuse to let my people go, behold, to morrow will I bring the locusts into thy coast:” I suspect the locusts mentioned here are somewhat like the grasshoppers in this country.  Back when I was young in the late 1950s we had a plague of grasshoppers that ruined many crops and ate much of the vegetation in our area.  The plague was so bad that we had at one time to stop hanging our clothes out on the clotheslines to dry.  The grasshoppers would chew holes in the clothes hanging on the clotheslines.  I also suspect that the plague of locusts that came upon Egypt was far greater than the plague had been upon us in our region of the country.   

“And they shall cover the face of the earth, that one cannot be able to see the earth: and they shall eat the residue of that which is escaped, which remaineth unto you from the hail, and shall eat every tree which groweth for you out of the field:” The plague of hail had destroyed many of the crops and broken the trees in Egypt.  This coming plague was to destroy what was left of the crops and eat all the green vegetation upon the trees.  In essence, it would completely destroy the crops and fruits of Egypt in that year.  The LORD was hitting hard on the economy and financial stability of Pharaoh and of Egypt.   

“And they shall fill thy houses, and the houses of all thy servants, and the houses of all the Egyptians; which neither thy fathers, nor thy fathers' fathers have seen, since the day that they were upon the earth unto this day.”  The promise of the plague of locusts was not only that they would eat the residue of the vegetation, but that they also would fill the houses of Pharaoh, his servants, and all the Egyptians.  Locusts are an unwelcome guest in just about anyone’s house.  That they would fill the houses would be a grief of mind to those who lived there.  The plague was to be the greatest plague of locusts that anyone alive in Egypt had ever seen.   

“And he turned himself, and went out from Pharaoh.”  When the LORD commands, the issue is not up for debate.  Moses knew this and after the proclamation was made, he left Pharaoh.