Literary: This is a formal lament. The Lord of the vineyard repeats the information that the efforts to salvage his tree have not succeeded. He catalogs his efforts. All of this background serves to give focus to the poignant question at the end, how has this occurred? In spite of the best efforts of the Lord of the vineyard, the tree appears to be lost. No blame for lack of care or trying can be laid at the door of the Lord. Who then is to blame?