The Cleansing of Isaiah and the Purging of Israel (Isaiah 6 and the Theology of Isaiah)

In preparation for a seminar I’ll be teaching on the theology of the Old Testament prophets, I’ve spent some time over the past few weeks reflecting on the message of the book of Isaiah. I’ve been reminded of the centrality of the story of Isaiah’s call in Isaiah 6 and how the prophet’s initial encounter with God impacted all of his ministry and message. Isaiah 6 is more than just Isaiah’s call as a prophet; in many ways, this passage presents the drama of the book of Isaiah in condensed form. God cleanses Isaiah to proclaim his message to Israel so that Israel might be cleansed to proclaim God’s glory to the nations. John Oswalt explains: “If the people of ‘unclean lips’ (6:5) can have the same experience that he, the “man of unclean lips” had, then the dilemma Isaiah sees in Israel, and which he expresses in chapters 1-5, can be solved. That dilemma is: How can the present corrupt, rebellious Israel (expressed in Judah), defying God’s instruction, ever become the promised, clean obedient Israel from whom all the nations will learn instruction.” (Isaiah, NIVAC, 125)

Yahweh is Holy and Israel is Not

Isaiah sees a vision of Yahweh as the thrice-holy God, and this image leaves a deep impression on his entire ministry. The title “Holy One of Israel” becomes one of the prophet’s favorite designations for God (this title appears 26 times in Isaiah and only 5 times in the rest of the OT). Yahweh is holy, but the problem is that Israel, his people are not. In the presence of this holy God, Isaiah becomes aware of his own sinfulness—he is a man of unclean lips. Being in the presence of a holy God as a sinful human is a dangerous thing, and Isaiah sees himself under a sentence of death (“Woe is me”). Rather than God’s presence providing comfort, the smoke and thunder bring terror—on an everyday visit to the Jerusalem Temple, the God of Sinai revealed himself in a powerful and frightening theophany. Even the “seraphim” (lit. “burning ones”) who serve in Yahweh’s presence inspire terror (the word is used elsewhere in the OT to refer to poisonous snakes; see Num 21:6; Deut 8:15; Isa 14:29; 30:6).

Israel is also a sinful people, and their empty worship makes it dangerous for them to enter into Yahweh’s presence (Isa 1:15-18). Yahweh hates their empty prayers and rituals. They are rebellious children who have spurned the Holy One of Israel (Isa 1:2-4). They are a worthless vineyard that has failed to produce the fruit that Yahweh has desired and demanded from them (Isa 5:1-7). Like Isaiah, they are particularly corrupted in their speech, “a people of unclean lips.” Rather than proclaiming God’s holiness, they declare their own sinfulness:

For Jerusalem has stumbled, and Judah has fallen, because their speech and their deeds are against the LORD, defying his glorious presence. For the look on their faces bears witness against them; they proclaim their sin like Sodom; they do not hide it. Woe to them! For they have brought evil on themselves. (Isa 3:8-9)

With their words, they defy God to punish them for their sinful behavior:

Woe to those who draw iniquity with cords of falsehood, who draw sin as with cart ropes, who say: "Let him be quick, let him speed his work that we may see it; let the counsel of the Holy One of Israel draw near, and let it come, that we may know it!" Woe to those who call evil good and good evil, who put darkness for light and light for darkness, who put bitter for sweet and sweet for bitter! (Isa 5:18-20)

The Cleansing of Isaiah and the Purging of Israel

Isaiah’s unclean lips render him unfit to speak as Yahweh’s messenger, and so a seraph must come with a burning coal to purge and cauterize his lips so that he can respond to Yahweh’s call (Isa 6:6-8). It is only after his cleansing that Isaiah can say, “Here am I! Send me.” Israel was commissioned as a nation to be God’s servant (Isa 41:8-9; 44:1-2; 45:4; 48:20), but its sins also prevented the nation from fulfilling its mission of declaring and reflecting God’s glory to the nations—Israel became a deaf and blind servant (Isa 42:18-22). Because of their sin, Israel cannot be God’s witnesses or declare his praise (cf. Isa 43:10, 21-22) and like Isaiah stands in need of cleansing so that it can fulfill its role as God’s servant. Isaiah immediately recognized his sinfulness while in the presence of Yahweh and instantly received cleansing and purging from Yahweh. Israel’s cleansing will not come so easily because the nation is blind and deaf toward the prophet’s calls to repentance and warnings of judgment (Isa 6:9-10). Yahweh can only cleanse his people through a severe judgment that purges away their dross and corruption (Isa 1:25-31). Israel’s obstinance is such that its judgment requires that its cities be left waste and without inhabitant (Isa 6:11-13).

The purging of Israel in the book of Isaiah is reflected through the transformation of Zion, with the city representing the nation as a whole. Barry Webb has stated that Zion’s transformation “is the key to both the formal and thematic structure of the book of Isaiah.” The Zion of Isaiah’s day had become a city of bloodshed, but Yahweh’s judgment would one day transform the city into a shining beacon of righteousness (Isa 1:21-26). The city that was left like “a hut in a melon field” (Isa 1:8) would one day be exalted as the highest mountain on earth (Isa 2:1-4). Because of God’s grace, the unfaithful harlot (Isa 1:21) would become a pure and holy bride (Isa 62:4). Yahweh would take back Daughter Zion, the wife he sent away with a certificate of divorce, and the barren city would be so filled with inhabitants that her walls could not contain them (Isa 49:14-18; 50:1; 54:1-8; 62:5; 66:6-11).

In the first stage of judgment, God sent the Assyrians as the rod of his anger (Isa 10:5), and Israel as a people was left bloodied and bruised with most of its cities burned with fire (Isa 1:5-8). Israel was left with only a few survivors (Isa 1:9), and even the tenth that remained would be subjected to a further burning (Isa 6:13). When King Hezekiah turned to the Lord for deliverance, Yahweh delivered Jerusalem from the Assyrians (Isa 36-37), but the purging was incomplete. Once the crisis was past, Judah returned to its sinful ways and refuseed to acknowledge Yahweh as its deliverer (Isa 22:1-14—esp. vv. 12-14). And so, the judgment that began with the invasion Assyrian invasion would continue with the exile to Babylon (Isa 39:5-7). Yahweh sent the Babylonian exile as a double punishment for Israel’s sins (Isa 40:2). As the exile came to an end, Yahweh was prepared to blot out Israel’s sin (Isa 43:25) and to wipe them out like a cloud (Isa 44:22). The goal of Yahweh’s judgment of his people all along was restoration, not destruction. With his judgment completed, he would act to remove the blindness that has characterized his failed servant (cf. Isa 29:9-10, 18; 35:5; 42:18-20; 48:8).

Because of Israel’s failure and inability to perform its role as the national servant, Yahweh ultimately completed the work of purging by raising up an individual servant. The individual servant was identified with Israel (49:3) and yet also had a ministry of restoring Israel to all that God intended her to be (Isa 49:6). While Israel was guilty before God and suffering for its own sins (Isa 48:4, 18; 50:1), the individual servant was absolutely faithful to God (Isa 50:4-9) and his suffering on behalf of the sins of others was ultimately what would restore Israel to God (Isa 53:4-6, 10-12). The restorative function of the individual servant’s work is reflected in that every use of the term “servant” after chapter 53 appears in the plural (Isa 54:17; 63:17; 65:8, 9, 13, 14, 15; 66:14). Because of the servant’s work, the Lord’s continual protection and blessing would be the “heritage” of Israel as his “servants” (Isa 54:17).

Like the prophet, the people of Israel would experience restoration and forgiveness when they were willing to acknowledge and confess their sins (Isa 59:12-14; 64:5-9). The people would ultimately come to the same recognition as the prophet on the day that he saw Yahweh in his glory, “We have all become like one who is unclean” (Isa 64:6). The seraph purged Isaiah’s lips, and Yahweh would also act in grace to remove sin from Israel. Yahweh promised that he would heal Israel’s sin (Isa 57:17-18) and when Israel lacked even the ability to return to him, Yahweh would act alone as warrior to rescue his people from their sin (Isa 59:15-20). Yahweh would complete his work of salvation by pouring out his Spirit on Israel so that the people would not return to their sinful ways (Isa 59:21).

Unfortunately, the blessings of Yahweh’s deliverance and the work of the servant would not extend to all of Israel. When returning from exile, Israel would persist in its sins of social injustice (Isa 58:1-14; 59:3-9, 14-15) and pagan worship (Isa 57:3-8; 65:1-7; 66:17) The prophet distinguished between those in Israel who would be Yahweh’s “servants” and those that would persist in their sinful ways and remain under his judgment. For those who disobey, being in the presence of Yahweh would remain a dangerous thing (Isa 66:1-4). Prior to the coming of the eschatological kingdom (“new heavens and earth”), the Lord will carry out a final purging judgment of Israel so that only those who are truly his “servants” will remain (65:8-16; 66: 15-16, 24).

The Proclaiming of Yahweh’s Glory to the Nations

In his initial vision, Isaiah saw that the glory of Yahweh filled the earth (Isa 6:3), and the agenda of his ministry became that Israel and ultimately all peoples would recognize the glory of Yahweh. More than any other book in the Old Testament, the book of Isaiah highlights the participation of the nations in God’s future kingdom, because the blessings of God’s glory were too great to belong to Israel alone.

It shall come to pass in the latter days that the mountain of the house of the LORD shall be established as the highest of the mountains, and shall be lifted up above the hills; and all the nations shall flow to it, and many peoples shall come, and say: "Come, let us go up to the mountain of the LORD, to the house of the God of Jacob, that he may teach us his ways and that we may walk in his paths." For out of Zion shall go the law, and the word of the LORD from Jerusalem. He shall judge between the nations, and shall decide disputes for many peoples; and they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore. (Isa 2:2-4)

In that day there will be an altar to the LORD in the midst of the land of Egypt, and a pillar to the LORD at its border. It will be a sign and a witness to the LORD of hosts in the land of Egypt. When they cry to the LORD because of oppressors, he will send them a savior and defender, and deliver them. And the LORD will make himself known to the Egyptians, and the Egyptians will know the LORD in that day and worship with sacrifice and offering, and they will make vows to the LORD and perform them. And the LORD will strike Egypt, striking and healing, and they will return to the LORD, and he will listen to their pleas for mercy and heal them. In that day there will be a highway from Egypt to Assyria, and Assyria will come into Egypt, and Egypt into Assyria, and the Egyptians will worship with the Assyrians. In that day Israel will be the third with Egypt and Assyria, a blessing in the midst of the earth, whom the LORD of hosts has blessed, saying, "Blessed be Egypt my people, and Assyria the work of my hands, and Israel my inheritance." (Isa 19:19-25)

"Turn to me and be saved, all the ends of the earth! For I am God, and there is no other. By myself I have sworn; from my mouth has gone out in righteousness a word that shall not return: 'To me every knee shall bow, every tongue shall swear allegiance.' (Isa 45:22-23)

Arise, shine, for your light has come, and the glory of the LORD has risen upon you. For behold, darkness shall cover the earth, and thick darkness the peoples; but the LORD will arise upon you, and his glory will be seen upon you. And nations shall come to your light, and kings to the brightness of your rising. (Isa 60:1-3)

As the restored servant of Yahweh, Israel would become a light to the nations (Isa 49:6), and the book of Isaiah concludes with the survivors of Israel going out to the nations to “declare the glory of the Lord” so that the nations might come to Zion and worship (Isa 66:18-21):

For I know their works and their thoughts, and the time is coming to gather all nations and tongues. And they shall come and shall see my glory, and I will set a sign among them. And from them I will send survivors to the nations, to Tarshish, Pul, and Lud, who draw the bow, to Tubal and Javan, to the coastlands afar off, that have not heard my fame or seen my glory. And they shall declare my glory among the nations. And they shall bring all your brothers from all the nations as an offering to the LORD, on horses and in chariots and in litters and on mules and on dromedaries, to my holy mountain Jerusalem, says the LORD, just as the Israelites bring their grain offering in a clean vessel to the house of the LORD. And some of them also I will take for priests and for Levites, says the LORD.

What God did for Isaiah in his call as prophet is ultimately what he would do for all of Israel. The cleansing of Isaiah so that he might fulfill his mission as Yahweh’s spokesman prefigured how Yahweh would cleans Israel through purging judgment so that Israel might fulfill its role as Yahweh’s servant by proclaiming his glory throughout the earth.