Exodus 5:1 And afterward Moses and Aaron went in, and told Pharaoh, Thus saith the Lord God of Israel, Let my people go, that they may hold a feast unto me in the wilderness. 2 And Pharaoh said, Who is the Lord, that I should obey his voice to let Israel go? I know not the Lord, neither will I let Israel go.
[Patriarchs & Prophets pp 758>759] Every Egyptian king considered himself as a “son of Ra,” and carried this expression in his titulary. When Amen of Thebes became chief god of Egypt during the eighteenth dynasty, the power of the sun god Ra was recognized as so great that a compromise was made by combining Amen and Ra to make one god—Amen-Ra. A few years after the Exodus, when Ikhnaton introduced a short-lived monotheism, the only god retained was Aton, the sun disk.
Seeing how entrenched sun worship was in the religious life of the Egyptians, and how highly the sun god Ra, Amen-Ra, or Aton was revered, we can understand why the plague directed against the god was brought upon Egypt toward the culmination of the fight between the God of the Hebrews and His Egyptian adversaries. Also, the tenth plague, the slaughtering of the first-born was striking at least one god, and that was the king, who was considered to be Horus, the son of Osiris.
As the ruler of the Nile country, he was addressed by his subjects as “the good god.” Hence, the last plague crowned the actions wrought by the miracle-working power of the Hebrew God. So far, the gods controlling the forces of nature or animals had been disgraced. But now, a god, living in a visible form among the Egyptians was also humiliated by the despised God of the Hebrew slaves, of whom the proud Pharaoh once had said, “Who is the Lord, that I should obey His voice to let Israel go?
Exodus 9:13 And the Lord said unto Moses, Rise up early in the morning, and stand before Pharaoh, and say unto him, Thus saith the Lord God of the Hebrews, Let my people go, that they may serve me. 14 For I will at this time send all my plagues upon thine heart, and upon thy servants, and upon thy people; that thou mayest know that there is none like me in all the earth. 15 For now I will stretch out my hand, that I may smite thee and thy people with pestilence; and thou shalt be cut off from the earth.
May God add His blessing to the study of His word. “Good night” and God bless!