“The declaration ‘what could have been done more to my vineyard’ is the same phrase used by the master of the vineyard in the allegory of Zenos (see Jacob 5:47). Although Zenos refers to the whole vineyard, and not just the ‘pleasant plant’ of Judah as designated by Isaiah, both conditions show that the Lord gives full opportunity within the framework of man’s agency, wherein man must choose and do his part” (Nyman, Great Are the Words of Isaiah, 43).