6:1 Two statements are made at the outset; the first roots this experience in the grim world of the eighth century BC, while the second opens up a vista onto a far greater reality. Both the seen and the unseen worlds are real, but it is the unseen that controls the big picture. Movement between the visible world of Isaiah’s Jerusalem and the world beyond time and space is characteristic of the book.

The opening statement (“In the year that King Uzziah died”17) is a foreboding one. If this king is known at all, it is usually because of this obituary notice. Yet he was one of the most remarkable of Judah’s kings. The account of him in 2 Chronicles 26:1–15 sees him as another David and another Solomon. Yet that text contains the chilling statement “He was marvelously helped, till he [became] strong” (2 Chron. 26:15). The rest of that chapter recounts his tragic decline, which reflects the nation’s own. At the time of his death he had reigned for fifty-two years (his last years were perhaps a co-regency with his son Jotham), and it was difficult to imagine life without him.

The connection between the statement “I saw the Lord sitting upon a throne” and the previous one is obvious. The king of Judah is dead, but Isaiah’s vision is filled with a king who can never die and a throne that can never be emptied. The temple here is not only the Jerusalem temple but the heavenly archetype, whose throne towers above all earthly powers.18

Language struggles to express the majesty of this God. The train of his robe suggests that though the highest heaven cannot contain him, he graciously touches earth (cf. 1 Kings 8:27–30). Symbolic language is used, but this is a real experience; God is there. And in the presence of his holiness the prophet and his readers are overwhelmed.

6:2 The seraphim (or the “burning ones”) stand “above him” (or “around him”). This does not imply superiority but rather that they are servants standing ready to do their master’s bidding, while he is seated. Fire is regularly associated with God and his holiness (e.g., Gen. 3:24; Ex. 3:1–6; Lev. 10:1–2; Dan. 7:9–11). The verbs “covered” and “flew” are participles, suggesting continuous action. Indeed, the seraphim perhaps resemble huge flames, adding to the overwhelming nature of the vision. Covering one’s face suggests reverence. Covering one’s feet possibly suggests an unwillingness to take one’s own path, or perhaps modesty. Flying suggests swiftness in carrying out God’s commands.

6:3 The angels’ worship expresses itself in antiphonal praise as they express the supreme holiness of God. Hebrew uses repetition to suggest superlatives, but this is the only text containing threefold repetition of an attribute of God. This is the fullest truth about him. Indeed, we might have to use a child’s word and say “God is holy to the gazillionth degree” in order to seek to understand this phrase. This is what God is in himself; all other holiness is derivative.

Yet the next clause (“The whole earth is full of his glory”) shows us that, although God is unapproachable in his transcendence, he reveals himself in the visible world and not only in the temple. His glory, his utter reality and blinding splendor, fills the earth. Ultimately, this will be expressed in the new creation (e.g., 11:1–9; 35:1–10; 60:1–3), but even now in the fallen world we see glimpses of it.

6:4 The assault on the senses continues as the doorposts and thresholds shake and the temple is filled with smoke. Possibly the threshold is mentioned because Isaiah does not dare to venture any further. The smoke suggests the presence of the God of Sinai (Ex. 19:18). This is another possible link between Isaiah and Moses, as in Isaiah 1:2, which echoes Deuteronomy 32:1. The Lord is shrouded in mystery.

6:5 As the prophet hears the pure worship of the seraphim, he is especially conscious not merely of the fact of his own sin but of the reality that his sin particularly relates to his speaking, as he bewails his “unclean lips.” As do other leaders such as Daniel (Dan. 9:3–19) and Ezra (Ezra 9:6–15), Isaiah identifies with the sin of the people. For Isaiah, called to preach, to admit that he has unclean lips would be a particularly painful confession. Thus he anticipates only judgment: “Woe is me! For I am lost.” He feels excluded from the worship of heaven and unable to carry out his work on earth.

6:6–7 Plainly, the prophet considers his case hopeless. Yet just as the initial vision was totally God’s initiative, so here his overwhelming grace is prominent as one of the seraphim is sent as a messenger of blessing. The blazing holiness of God, dramatized by the seraphim and the burning coal, becomes the means of salvation. The altar where fire burns continually (Lev. 16:14–19) shows the true nature of forgiveness. In chapter 1, Isaiah condemned the people for ritual offerings that did not affect heart and life. This offering, however, atones for—“covers”—the prophet’s sin, so that he stands cleansed and forgiven.

More than that, this cleansing meets him at the immediate point of need: his mouth. It provides both inward and outward cleansing. “Guilt” is the inner attitude that causes wrong behavior, whereas “sin” is the specific outward expression of this attitude. Isaiah now has “clean hands and a pure heart” (Ps. 24:4).19

The humbled and cleansed prophet is no longer on the threshold but is near enough to hear the voice of the Lord. The Lord is surrounded by his entourage, the heavenly court or divine council (cf. 1 Kings 22:19–23), and the prophet is permitted to listen. It would also be right to see here one of the OT’s foreshadowings of the Trinity, not least because these verses are related to Jesus (John 12:41) and the Spirit (Acts 28:25). Obviously, this is not yet the full revelation of the NT, but it is certainly compatible with what is to come.

6:8 Although the Lord’s words are not addressed directly to Isaiah, he immediately offers himself as a messenger. There is a subtle blend here of volunteering (“go”) and compulsion (“send”). Yet the message about to be given is daunting in the extreme.

6:9–10 On the face of it, this seems a bizarre message. Isaiah is to go and tell people that they will not understand, however much they listen. Indeed, he is to make sure that they do not. Some have argued that these words are not original to this context but are written much later, when the people’s rejection of the word has become obvious. This reflects more of a problem in the minds of the interpreters, for there is no evidence that the prophet himself senses any such problem. Isaiah realizes after his experience in the temple that only radical cleansing could fit sinful people for the presence of a holy God. The word that alone can heal will bring judgment if rejected, yet it still must be preached. Isaiah’s generation will not listen and in their pride will pass the point of no return. Yet in the ultimate grace of God, the same message will save future generations if they indeed heed it.

The importance of this message is emphasized by its use in the NT. Matthew 13:14–15 uses it of the rejection of the Messiah himself when he comes and his preaching leads to further rejection. Paul also quotes this to Jewish leaders (Acts 28:26–27) and predicts that the Gentiles will listen (an issue he wrestles with deeply in Romans 9–11). Since this is the only message that can truly heal, any attempt to water it down will lead only to false hope (such as is peddled by the false prophets who opposed Jeremiah; e.g., Jeremiah 23).

6:11–12 Understandably, the prophet shrinks from the implications of his call. He will obey, but he wonders if there is any hope in the end, using language familiar from the lament psalms (e.g., Pss. 6:3; 94:3). The Lord’s answer gives little comfort, as it anticipates devastation and exile: first for the northern kingdom, taken off to Assyria during Isaiah’s own lifetime, and then for Judah, who will later be exiled to Babylon. At this moment Assyria is the main threat, but Isaiah sees beyond the immediate danger. This will be the particular theme of chapter 39. The exile to Babylon will not be a historical accident; it is Yahweh who will send them into exile, fulfilling the covenant curses of Deuteronomy 28:36.

6:13 Is there, then, no hope at all? The devastation will be complete, and the nation will be like a great tree that lies where it has fallen. There will be a remnant, though, and that remnant will have life in it. Such hope is small at the moment, but it will eventually burst into life. Indeed, one particular figure is spoken of: “a shoot from the stump of Jesse” (Isa. 11:1), that is, a Davidic king who will eventually come to and from the remnant. In Luke 1–2 the remnant is very small: essentially Mary and Joseph, Elizabeth and Zechariah, Simeon, and Anna. Where there is an “offspring of evildoers” (Isa. 1:4) there will one day be a “holy seed.” God will not finally abandon his people. In many ways this chapter is a concise summary of the themes of the whole book.