The hedge functions as one enclosure while the wall functions as a second enclosure as in the Persian custom, which was common for gardens in the Middle East. There is also some similarity between the tree of life and the tree of knowledge with the tower and wine vat positioned in Isaiah's vineyard (Isaiah 5:2). Both the tower and the wine vat may represent the source of life and the need for humans to make a decision between adhering to God's laws and transgression although this comparison is not explicit in the parable of the vineyard. The tower could also symbolize the temple and the wine vat the alter sacrifices were made.
THE VINEYARD: THE NATION OF ISRAEL AND PEOPLE.
A vineyard or kerem (H37654) in Hebrew is a place where grapes are grown. Because grapes do not produce abundant fruit when left to grow wild, the concept of a vineyard implies that someone is tending the vines to ensure that the vines are well cultivated. The description in Isaiah 5:1-2 emphasizes the care in the cultivation of the vineyard. The detail suggests that no effort was spared in providing conditions to allow the domesticated vines to thrive. The detail also makes it clear that the ability of the vineyard to thrive depends on God's willingness to tend the vineyard, with God as the caretaker looking after the needs of vineyard.3 Isaiah 5:3 suggests that the men of Judah are the vineyard, the plants of the Lord. Isaiah 5:7 also directly identifies the Lord as responsible for tending the vineyard and associates vineyard with the house of Israel. Using the concept of a vineyard as a metaphor for people or groups is not unique to Isaiah. Micah prophesizes that the Lord will punish Samaria: "Therefore I will make Samaria as a heap of the field, [and] as plantings of a vineyard" (Micah 1:6). Solomon describes his beloved as "a cluster of henna blossoms in the vineyards of Engedi" (Sol. 1:14). Referring to the people of Israel as a vineyard is also found elsewhere in scripture.