The discussion between Yahweh and his servant (Isa 49:3-49:4)

“Yahweh said to me.

‘You are my servant!

Israel!

I will be glorified in you.’

But I said.

‘I have labored in vain.

I have spent my strength

For nothing,

For vanity.

Yet surely my cause is with Yahweh.

My reward is with my God.’”

Second Isaiah has Yahweh call his servant Israel, not Isaiah. Yahweh was going to be glorified in his servant. However, the servant responded that he had labored in vain, spending all his strength on nothing but useless things. Nevertheless, this servant was willing to say that his cause was with Yahweh. He expected his reward from his God.