What does Exodus 7:4 mean?
God is reassuring Moses (Exodus 6:1–6) that everything is happening according to a divine plan (Exodus 3:19–20). Pharaoh rejected the initial request to free the Hebrew slaves (Exodus 5:6–9). He will continue to do so, first from his own obstinate attitude (Exodus 7:14; 8:15; 9:7), and later through God's example-making judgment (Exodus 9:12; 10:1; 14:8).This resistance is not a sign that the Lord's plan is being thwarted. Rather, it is part of the plan. God intends to send a clear message about His own power (Exodus 7:2–4). He also seeks to establish His unique relationship with the nation of Israel (Exodus 6:6–7). After ten devastating plagues, there will be no doubt that the Lord is supreme (Expodus 7:5), and that His people were freed entirely by His power (Exodus 12:41).
Despite advanced age (Exodus 7:7), Moses and Aaron will faithfully continue to obey the Lord's instructions (Exodus 7:6).
Exodus 7:1–7 completes the encouragement and summary which began in chapter 6. God intends to free Israel (Exodus 1:11–14) through spectacular miracles. These will demonstrate His power. Moses and Aaron (Exodus 4:14–16) will obey, despite both men being more than eighty years old.
God again repeats (Exodus 3:19–20; 4:19–23; 6:6) the basic outline of how Israel will be freed from Egyptian slavery (Exodus 1:11–14). He then commands Moses and Aaron to show Pharaoh one of the miraculous signs given for that purpose (Exodus 4:2–5). Egyptian magicians seem to duplicate the feat, so Pharaoh still refuses to hear Mo-ses' message. This results in the first plague: all water in Egypt, including the Nile river, becomes blood. This lasts seven days. The Lord then tells Moses to repeat the demand for Israel's release.