Exodus 11:4 - Joseph Benson’s Commentary on the Old and New Testaments

I will go out into the midst of Egypt By an angel, who, as appears from Exodus 12:23, was ordered to do this execution. The whole series of the narration shows that this verse connects with the end of the preceding chapter, and that the following denunciation was pronounced by Moses at that time, before he went out from Pharaoh.