During all this time the persecuted Israelites were praying to the true God to be delivered from the slavery of the Egyptians, who were idolaters. One day Moses saw a bush burning; and as he came near to look at it, he heard a voice telling him not to come too near, and bidding him take off his shoes, for he was on holy ground. (Ex. 3). It was God who thus appeared and spoke to him, and He ordered him to take off his shoes as a mark of respect and reverence. When we want to show our respect for any person or place, we take off our hats; but the people of that country, instead of their hats, took off their shoes. It was the custom of the country and did not seem strange to them.
Then God told Moses that He was going to send him to deliver His people from the Egyptians and lead them back to their own country; and He sent Aaron, the brother of Moses, with him. Then Moses said to God, the king of Egypt will not let the people go, and what can I do? God gave Moses two signs or miracles to show the king, so that he could know that Moses was really sent by Him. He gave him power to change a rod into a serpent, and back again into a rod; power also to bring a disease instantly upon his hand, and to heal it instantly. (Ex. 4). Do these, said Almighty God, in the presence of the king. Then Moses and Aaron went to the king and did as God commanded them; and when the rod of Aaron became a serpent, the king’s magicians—that is, men who do apparently wonderful things by sleight of hand or the power of the devil—cast their rods upon the ground, and they also became serpents—not that their rods were changed into serpents, but the devil, who was helping them, took away instantly their rods and put real serpents in their place—but Aaron’s serpent swallowed them up. (Ex. 7). After these signs the king would not let the people go with Moses; for God permitted the king’s heart to be hardened, so that all the Egyptians might see the great work God was going to do for His people.
Then God sent the ten plagues upon the Egyptians, while the Israelites—God’s people—suffered nothing from these plagues.