(Closely related Posting: Nature, tone, speakers & audiences of the Isaiah 8:5-10 bible passage )
This is just a theory. If you think about some ministries like Mark Virkler's ministries ( https://www.cwgministries.org/ ) that encourages Christians to journal, it would be kind of interesting if we could view Some bible passages like journaling.
I've spoken to Pentecostal/Charismatic Christians who immediately journal when they awaken from sleep after some meaningful dream( regardless of whether it was a nightmare or just a meaningful dream).
Please keep in mind that Isaiah was known as one of the many "writing prophets".
Lets try to think about Isaiah's Spiritual/Mental/Emotional/Physical progressing state as we read (Isaiah 8:5-12):
Isaiah 8:5-12 (New American Standard Bible 1995
5 Again the Lord spoke to me further, saying,
6 “Inasmuch as these people have rejected the gently flowing waters of Shiloah And rejoice in Rezin and the son of Remaliah; 7 “Now therefore, behold, the Lord is about to bring on them the strong and abundant waters of the [a]Euphrates, Even the king of Assyria and all his glory; And it will rise up over all its channels and go over all its banks. 8 “Then it will sweep on into Judah, it will overflow and pass through, It will reach even to the neck; And the spread of its wings will fill the breadth of your land, O Immanuel.
9 “Be broken, O peoples, and be [d]shattered; And give ear, all remote places of the earth. Gird yourselves, yet be [e]shattered; Gird yourselves, yet be [f]shattered. 10 “Devise a plan, but it will be thwarted; State a [g]proposal, but it will not stand, For God is with us.”
11 For thus the Lord spoke to me [i]with mighty power and instructed me not to walk in the way of this people, saying,
12 “You are not to say, ‘It is a conspiracy!’ In regard to all that this people call a conspiracy, And you are not to fear [j]what they fear or be in dread of it.
(Isaiah 8:5-8) could be seen as some sort of Godly revelation of some predicted doom & gloom events regardless of whether Isaiah had a nightmarish dream Or whether Isaiah had some shocking/arresting Godly revelation like Paul did on his road to Damascus.
Therefore, Isaiah "writes" ( in today's lingo it's "journaling" ) down (Isaiah 8:9-10) , and then immediately "journals" an attempt to declare a countermanding/nullifying statement.
Does that sound reasonable?