Isa 5:1 Now will I sing to my wellbeloved a song of my beloved touching his vineyard. My wellbeloved hath a vineyard in a very fruitful hill:
God sings to his beloved, a song and a parable. The vineyard planted in a very fruitful Hill. God's people planted in Jerusalem, were his beloved.
Isa 5:2 And he fenced it, and gathered out the stones thereof, and planted it with the choicest vine, and built a tower in the midst of it, and also made a winepress therein: and he looked that it should bring forth grapes, and it brought forth wild grapes.
God protected the city and it's people, the place was given the choicest word of God; the law and the prophets. The people were to share the word of God and bring forth fruit. There should have been an abundance of good fruit, but instead they brought forth wild grapes. They went to a different seed, the seed of false gods and false beliefs.
Isa 5:3 And now, O inhabitants of Jerusalem, and men of Judah, judge, I pray you, betwixt me and my vineyard.
Isa 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?
God provided the seed of his word, His presence was in the temple and yet the people willfully disobeyed him. God does not force people to serve him. What more could he do? The fruit was wild, inferior, as if God had not planted his seed on fertile ground. The people behaved like pagans in the midst of Gods blessings and provision for them. America fits this description; we are ripe for judgment.