CLAIM: When Isaiah gets his calling to be a prophet, God tells him, “Render the hearts of this people insensitive, their ears dull, and their eyes dim, otherwise they might see with their eyes, hear with their ears, understand with their hearts, and return and be healed” (Isa. 6:10). Did God send Isaiah so that the people would not repent?
RESPONSE: This is certainly a difficult passage to interpret. However, there are a number of reasons why Isaiah is not referring to fatalism here:
First, this passage might be using rhetorical language to make a point. By telling the people to “Keep on listening, but do not perceive; keep on looking, but do not understand” (Isa. 6:9), Isaiah could be using rhetoric. For instance, a physical trainer might tell an Olympic athlete: “Go ahead and eat doughnuts for breakfast… There’s no need for you to hit the gym… No! You can sleep in every day, and I’m sure you’ll still do just fine when you compete!” This is a way of inculcating a sense of motivation in the athlete by using sarcasm and rhetoric.
Second, God could be alluding to idolatry. The psalmist refers to idols as deaf and dumb (Ps. 115:5-7; 135:16-17), and later in his book, Isaiah describes idols this way, too (Isa. 44:18). Isaiah could be commenting on how the idol worshippers could be similar to their idols: deaf and dumb to the calls of God. In a sense, Isaiah could be claiming that “you become what you worship.”
Third, God later uses Isaiah to preach repentance. Later in his book, Isaiah writes, “In repentance and rest you will be saved” (Isa. 30:15). In the very next chapter, God pleads with the faithless king Ahaz to repent and turn to him (Isa. 7:4-9). Therefore, without human responsibility, these calls for repentance would be absurd. The reason that the people reject Isaiah’s message is because they viewed it as too simple. Isaiah 28:9 states, “To whom would He teach knowledge, and to whom would He interpret the message? Those just weaned from milk? Those just taken from the breast?” The people rejected this passage because it seemed too simplistic to them. Grogan argues that this could be a form of judicial hardening, because the people had rejected God for centuries.
Fourth, God has perfect foreknowledge of all future events. God tells Isaiah that he knows “the end from the beginning” (Isa. 46:10). Therefore, God knew in advance whether or not the people would repent. However, God’s foreknowledge of these events does not eliminate human responsibility. Instead, God knew what these people would freely choose. Foreknowledge is not the same as foreordination. Consider the difference between a thermostat and a thermometer. A thermostat changes or controls the temperature of a house, while a thermometer measures or knows the temperature. In the same way, God knew that these people would not repent, but he was not forcing them to not repent.
Jesus cited this passage to explain how people would reject his message of forgiveness (Mt. 13:14-15), and Paul claimed that this passage predicted how many Jewish people would reject Christ, but the Gentiles would accept him (Acts 28:28; Rom. 11:8). But, of course, these Jewish people had a decision in accepting or rejecting Christ’s message of love and forgiveness. The Bible unambiguously teaches that God desires all men to come to repentance (1 Tim. 2:4; 2 Pet. 3:9).
Fifth, God gave this message of the future to Isaiah—not the nation of Israel. By telling Isaiah about the reaction of the people, God was preparing Isaiah for his personal commission in ministry. He was not trying to be fatalistic about the nation; instead, he was trying to be realistic with Isaiah.
In conclusion, the people could not repent, because they would not repent. For the NT usages of this passage, see Mathew 13:14-15; Mark 4:10-12; Luke 8:10; John 12:39-41; Acts 28:26-27; Romans 11:8.
 Grogan, G. W. (1986). Isaiah. In F. E. Gaebelein (Ed.), The Expositor’s Bible Commentary: Isaiah, Jeremiah, Lamentations, Ezekiel (Vol. 6, p. 58). Grand Rapids, MI: Zondervan Publishing House.