Moses and Aaron were now key figures in a ‘battle of the gods.’ In the persons of the magic-practicing priests, the chiefs of whom were apparently named Jannes and Jambres (2Ti 3:8), Pharaoh summoned the power of all the gods of Egypt against the power of Jehovah. The first miracle that Aaron performed before Pharaoh at Moses’ direction proved Jehovah’s supremacy over the gods of Egypt, even though Pharaoh became more obstinate. (Ex 7:8-13) Later, when the third plague occurred, even the priests were forced to admit, “It is the finger of God!” And they were so severely stricken by the plague of boils that they were altogether unable even to appear before Pharaoh to oppose Moses during that plague.​—Ex 8:16-19; 9:10-12.

Plagues do softening and hardening work. Moses and Aaron became the announcers of each of the Ten Plagues. The plagues came as announced, proving Moses’ commission as Jehovah’s representative. Jehovah’s name was declared and much talked about in Egypt, accomplishing both a softening and a hardening toward that name​—softening the Israelites and some of the Egyptians; hardening Pharaoh and his advisers and supporters. (Ex 9:16; 11:10; 12:29-39) Instead of believing that they had offended their gods, the Egyptians knew that it was Jehovah who was judging their gods. By the time nine plagues had been executed, Moses too had become “very great in the land of Egypt, in the eyes of Pharaoh’s servants and in the eyes of the people.”​—Ex 11:3.

Moreover, there were the religious leaders, the magic-practicing priests, chief among Moses’ opposers. These men were, aside from Pharaoh himself, the most powerful men in the realm. All this impressive array was aligned to back up Pharaoh in support of the gods of Egypt. And Moses and Aaron came before Pharaoh, not once, but many times, Pharaoh’s heart getting harder each time, because he was determined to keep his valuable Hebrew slaves under his domination. In fact, after announcing the eighth plague, Moses and Aaron were driven out from before Pharaoh, and after the ninth plague they were ordered not to try to see Pharaoh’s face again on pain of death.​—Ex 10:11, 28.