Hi @vjtorley,
Thanks for sharing this video! I still don’t think the Servant can be Israel, though.
It certainly is the prophet speaking on behalf of a group of people (unless you think the kings are actually writing this portion of the oracle?), the question is whether that group of people is the kings of the gentiles or the people of Israel. The speakers could be the kings of the gentiles, but why are they then referred to as wandering sheep without a shepherd, which as far as I’m aware is a metaphor only used to describe the people of Israel?
Deutero-Isaiah also refers to Israel as “servant,” indeed, but he draws important contrasts between the Israel-servant and the servant of the songs. I don’t see how the servant who opens the eyes of the blind could be the Israel-servant who is blind; the servant who refuses to even break a bruised reed could be the Israel-servant who will make the nations “like chaff”; the servant who is a “covenant to the people” could be the Israel-servant who is “the people”; the servant who “was not rebellious” could be the Israel-servant who was “a rebel from birth”; and so on.
“Did Isaiah believe in the Trinity?” (9:47) — No he certainly didn’t. The doctrine of the Trinity wasn’t fully developed until the fourth century AD, so how could an 8th-century BC Israelite prophet (or the 6th-century BC author of Deutero-Isaiah) possibly believe in it? I doubt you could even find a single trinitarian scholar who argues, on exegetical grounds, that Isaiah believed in the Trinity.
Rabbi Tovia Singer makes a very interesting point about the plural pronoun in Isaiah 53:8. I really don’t know how to respond to this, but I also note that the same verse says that the servant died “for the transgression of my people.” Now the possessive pronoun here (“my”) is in the first-person singular, I checked an interlinear to confirm this, so it’s Yahweh speaking here. If the servant is the people of Israel, how is it that he died (unjustly) for the sins of the people of Israel?