Isaiah 6:1-8, the First Reading appointed for the 5th Sunday after Epiphany in the Year of Luke, is clearly a call narrative. It is matched with Jesus' call to Simon in Luke 5, the Gospel reading appointed for this day. It will be the preacher's joyful task to bring this call to her or his listeners.
(The following questions are not meant to be exhaustive, but are best used in conjunction with other sets of questions available to exegetes. These questions are meant to lift up the function of the Word in the text, a central concern of Law and Gospel preachers. For more on this method and Law and Gospel preaching in general, see my brief guide, Afflicting the Comfortable, Comforting the Afflicted, available from wipfandstock.com or amazon.)
1. How does the Word function in the text? The opening verses announce the holiness of the Lord of hosts, and as such, function as Law. The writer cries out, "Woe is me!" This is the appropriate response to the Law. The Gospel is present also, as the seraph touches the prophet's mouth and announces that "your guilt has departed and your sin is blotted out."
2. With whom are you identifying in the text? We are those to whom this Word is spoken. We are those who call out "Woe is me!" and those whose sin is taken away.
3. What, if any, call to obedience is there in this text? The call to obedience comes in the last two verses as the prophet responds to the need for someone to go forth to speak God's word.
4. What Law/Gospel couplet is suggested by this text? Using the words of the text we can readily imagine several couplets: guilty/guilt is taken away; sinful/sin is blotted out.
5. Exegetical work: The lexicon defines 'unclean lips' in this passage as "defiled of name, infamous." (The New Brown-Driver-Briggs-Gesenius Hebrew-English Lexicon, p. 379). Since 'unclean' can mean many things in Biblical passages (e.g. ritually unclean, morally unfit, polluted) it is important to understand that the prophet is announcing his public identity as one unfit for God's service living amongst a community.unfit for God's service. The prophet is coming to terms with the profound corruption already taken root in Judah and Jerusalem and in his own heart. It is then more important to understand the gift of grace given him when the seraph touches his mouth and announces he is forgiven. St. Jerome, in his commentary on this passage, notes that immediately upon announcing this forgiveness the Lord issues the call to service: "As long as Isaiah's tongue was treacherous and his lips unclean, the Lord does not say to him, Whom shall I send, and who shall go? His lips are cleansed, and immediately he is appointed the Lord's spokesman; hence it is true that the person with unclean lips cannot prophesy, nor can he be sent in obedient service to God." (Ancient Christian Commentary on Scripture, OT, vol. X, p. 55).
6. How does the Crossings Community model work with this text? Steve Albertin, in his complete 2015 analysis, shows how clearly this text exhibits the three ways the Word functions: As Law, as Gospel, and as Call to Obedience. "Woe is me!" is the call of every person when confronted with a holy God. "Your sin is blotted out" is the word of the Gospel, and "Send me!" is the response of all the redeemed to the call of obedience. This analysis is archived under its reference for Trinity Sunday.
Blessings on your proclamation!