These two rhetorical questions are really statements emphasizing that Yahweh could not have done anything more than what he did to ensure a good harvest of grapes. Although the previous verse called for the people to make a decision concerning who is at fault, the implied answer to the rhetorical questions is that Yahweh is not at fault. The vineyard (that is, the people) is obviously in the wrong, no matter what excuse it might offer.

What more was there to do for my vineyard, that I have not done in it?: This question implies that Yahweh had done all that could be done. The Hebrew verb ʿasah (“do”) again appears twice as the keyword. Translators may use a statement here (see second model below) or retain the rhetorical question.

When I looked for it to yield grapes, why did it yield wild grapes?: This question may also be treated as a strong statement. For yield grapes and yield wild grapes, see the comments on Isa 5.2.

Alternative translation models for this verse are:

• What more could I have done for my vineyard that I had not already done?
Why did it give sour grapes when I expected it to give fine grapes?

• There was nothing further I could have done for my vineyard
to ensure that it gave fine grapes.
I hoped it would give such fine grapes;
it should not have produced sour ones.

Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .