4 Moses had announced to Pharaoh, "This is what the Lord says: At midnight tonight I will pass through the heart of Egypt. 5 All the firstborn sons will die in every family in Egypt, from the oldest son of Pharaoh, who sits on his throne, to the oldest son of his lowliest servant girl who grinds the flour. Even the firstborn of all the livestock will die. 6 Then a loud wail will rise throughout the land of Egypt, a wail like no one has heard before or will ever hear again. 7 But among the Israelites it will be so peaceful that not even a dog will bark. Then you will know that the Lord makes a distinction between the Egyptians and the Israelites. 8 All the officials of Egypt will run to me and fall to the ground before me. 'Please leave!' they will beg. 'Hurry! And take all your followers with you.' Only then will I go!" Then, burning with anger, Moses left Pharaoh. 9 Now the Lord had told Moses earlier, "Pharaoh will not listen to you, but then I will do even more mighty miracles in the land of Egypt." 10 Moses and Aaron performed these miracles in Pharaoh's presence, but the Lord hardened Pharaoh's heart, and he wouldn't let the Israelites leave the country.
Matthew Henry's Commentary on Exodus 11:4-15
Commentary on Exodus 11:4-10
(Read Exodus 11:4-10)
The death of all the first-born in Egypt at once: this plague had been the first threatened, but is last executed. See how slow God is to wrath. The plague is foretold, the time is fixed; all their first-born should sleep the sleep of death, not silently, but so as to rouse the families at midnight. The prince was not too high to be reached by it, nor the slaves at the mill too low to be noticed. While angels slew the Egyptians, not so much as a dog should bark at any of the children of Israel. It is an earnest of the difference there shall be in the great day, between God's people and his enemies. Did men know what a difference God puts, and will put to eternity, between those that serve him and those that serve him not, religion would not seem to them an indifferent thing; nor would they act in it with so much carelessness as they do. When Moses had thus delivered his message, he went out from Pharaoh in great anger at his obstinacy; though he was the meekest of the men of the earth. The Scripture has foretold the unbelief of many who hear the gospel, that it might not be a surprise or stumbling-block to us, Romans 10:16. Let us never think the worse of the gospel of Christ for the slights men put upon it. Pharaoh was hardened, yet he was compelled to abate his stern and haughty demands, till the Israelites got full freedom. In like manner the people of God will find that every struggle against their spiritual adversary, made in the might of Jesus Christ, every attempt to overcome him by the blood of the Lamb, and every desire to attain increasing likeness and love to that Lamb, will be rewarded by increasing freedom from the enemy of souls.