John Calvin Commentary Isaiah 5:4

"What could have been done more to my vineyard, that I have not done in it? wherefore, when I looked that it should bring forth grapes, brought it forth wild grapes?" — Isaiah 5:4 (ASV)

What more ought to have been done to My vineyard? He first inquires what could have been expected from the best husbandman or householder, which He has not done to His vineyard? Therefore, He concludes that they had no excuse for having basely withheld from Him the fruit of His toil.

How did I expect that it would yield grapes? In this clause, He appears to expostulate with Himself for having expected any good or pleasant fruit from such a wicked people. This is much like when the result does not meet our expectation: we complain about ourselves and are angry at having misplaced our labor on ungrateful individuals whose wickedness should have restrained us from doing what we did. We then acknowledge that we are justly deceived because we were too naive and easily imposed upon.

But a more natural interpretation is this: “Since I discharged every part of My duty, and did more than anyone could have expected in tending My vineyard, how is it that it yields Me so poor a return, and that, instead of the fruit that was expected, it yields what is absolutely bitter?”

If it is objected that God had the remedy in His hands—if He had turned the hearts of the people—this is an idle evasion for those individuals. For their conscience holds them fast, so that they cannot escape by blaming another. Though God does not pierce the hearts of people by the power of His Spirit to make them obedient to Him, yet they will have no right to complain that this was lacking. For every pretense of ignorance is fully and abundantly taken away by the outward call. Besides, God does not speak here of His power, but declares that He was not under any obligation to do more than He did.