Jamieson, Fausset and Brown on Isaiah 5:7

7. Isaiah here applies the parable. It is no mere human owner, nor a literal vineyard that is meant.

vineyard of the Lord--His only one (Ex 19:5; Am 3:2).

pleasant--"the plant of his delight"; just as the husbandman was at pains to select the sorek, or "choicest vine" (Is 5:2); so God's election of the Jews.

judgment--justice. The play upon words is striking in the Hebrew, He looked for mishpat, but behold mispat ("bloodshed"); for tsedaqua, but behold tseaqua (the cry that attends anarchy, covetousness, and dissipation, Is 5:8, 11, 12; compare the cry of the rabble by which justice was overborne in the case of Jesus Christ, Mt 27:23, 24).