The Lord proceeded to give Isaiah specific instructions about what He wanted him to do and what the prophet could expect regarding his ministry (vv. 9-10), his historic-political situation (vv. 11-12), and his nation's survival (v. 13).
6:9 God sent Isaiah back to the people among whom he lived, a people with unclean lips (v. 5). He was to tell them to listen and to look at the revelations he brought from God, but they would not understand what the prophet meant fully (cf. Deut. 29:2-4).
6:10 The effect of Isaiah's preaching would not be that the people would repent but that they would harden their hearts against his messages (cf. Matt. 13:14-15; Mark 4:10-12; Luke 8:10; John 12:39-41; Acts 28:26-27; Rom. 11:8).
The Apostle John quoted this verse (and 53:1) in reference to the Jews' inability in Jesus' day to believe on Him (John 12:40). John then added, "These things Isaiah said, because he saw His glory, and he spoke of Him"(John 12:41). Isaiah realized that his words had prophetic significance as well as being applicable to his own situation.
". . . this chapter immediately follows and precedes examples of wrong reaction to God's word [5:24; 7:10-12]."81
God told Moses before he went to Pharaoh with the Lord's message that the Egyptian king would harden his heart (Exod. 3:19).82In both cases, Moses' commission and Isaiah's, God was not ruling out the possibility of repentance from the start. He was letting His prophet see beforehand what the outcome of his ministry would be. In both cases, too, those who heard God's word had the opportunity and the ability to respond to it positively, but they chose to respond negatively. Consequently God hardened their hearts in a judicial sense so it became harder, and eventually impossible, for them to repent (Exod. 10:1; cf. Rom. 1:18-32; Heb. 6:4-6). The Israelites in Isaiah's day had already hardened their hearts against the Lord, and His retributive judgment on them had already begun when Isaiah received his commission.
"The elect are not saved because they are creatures of light; they too were creatures of darkness and in them there was no goodness, nothing that would attract the light. God, however, out of His mere good pleasure did choose them and ordain them to life eternal, and when the blessed gospel was heard by them, they were given a heart that was then willing and able to hear and to respond. Those, however, whom God did not ordain to life eternal, He passed by and for their sin ordained to dishonor and wrath."83
The success of our ministry should not be our prime motivation to continue in the work of the gospel. Our loving commitment to remain faithful to the Lord who has graciously saved us and called us into His service despite our lack of outward success should be.
6:11-12 The news that the Israelites would harden their hearts against Isaiah's message undoubtedly disappointed the prophet. So he asked the Lord how long he should continue to preach. The Lord did not give him a certain number of years but implied that he should continue preaching until the full extent of God's judgment on the people because of their unresponsiveness had come. The penalty for resisting the Lord set forth in the Mosaic Covenant culminated in military defeat and exile from the Promised Land (Lev. 18:25-27; Deut. 28:21, 63; 29:28). The Lord took full responsibility for this judgment, though He used other nations as His instruments to execute it.
6:13 Yet there was hope. A tenth of the nation would survive, but even that minority would again face judgment. This probably refers to the remnant left in the land when Nebuchadnezzar took the majority captive to Babylon (2 Kings 24:14). When the nation was thoroughly cut down and burned, there would be a little spiritual life in it that would eventually sprout. This happened when a small number of godly exiles under the leadership of Zerubbabel, Nehemiah, and Ezra returned to the land and reestablished the nation. Antiochus IV of Syria almost consumed even this remnant during the inter-testamental period. They were the initial holy seed (cf. 41:8; 43:5; 53:10; 59:21; 65:9; 66:22; 1 Kings 19:18; Rom. 11:5), but Messiah would be the ultimate holy seed (Heb. zera, a collective singular; cf. 4:2; 11:1) who would arise out of the chastened nation.
