Who was Isaiah talking about?

Dale Tuggy asks:

We can ask here, of whom is Isaiah speaking? Who is this YHWH? We might well think it is the Father, since the NT plainly presupposes that the Father of Jesus and the one true God Yahweh are one and the same. Of course then anyone else, would not be the one true God.

 

But if I understand him, Steve thinks Isaiah there speaks of the one perfect Self, who later, we learn, is the Trinity. Isaiah of course doesn’t say anything about whether or not this perfect Self contains or is somehow composed of other selves.

That’s a good question, but ambiguous, for we need to distinguish between original intent and the objective referent. To take a comparison:

“Did you see Dylan at the costume ball last night?”

“No, I didn’t.”

Is the answer true or false? Depends. Maybe I did see Dylan, but since he was in disguise, I didn’t know who it was.

I saw Dylan, but I didn’t recognize Dylan in the mask. I saw him, but I didn’t see that it was him. Put another way, a difference between sight and perception.