The Lord's Words in Jeremiah's Mouth

Jeremiah's mouth and lips are prepared for speech. In Ezekiel's call, like Isaiah, he witnesses a Theophanic vision and he has given a scroll to eat. However, while the passages describing Jeremiah and Ezekiel's prophetic calls open their respective books, Isaiah's is found six chapters in. This puzzles many commentators as chapter 6 verse 1 to 8 has many of the expected features of an inaugural commission. Commentators have sought an explanation for this in speculative reconstructions of the redaction history of the text. John Oswald suggests that it would be better to focus instead upon the final canonical form of the text and the call narrative in its actual situation.