TSK
Treasury of Scripture Knowledge references in NET.
But on that day I will mark off the land of Goshen, where my people are staying, so that no swarms of flies will be there, that you may know that I am the LORD in the midst of this land.
The blood will be a sign for you on the houses where you are, so that when I see the blood I will pass over you, and this plague will not fall on you to destroy you when I attack the land of Egypt.
Then once more you will see that I make a distinction between the righteous and the wicked, between the one who serves God and the one who does not.