What does Isaiah 27:3 mean?
Isaiah's depiction of a vineyard contrasts with an earlier song (Isaiah 5:1–7). In both, the Lord is the keeper, and the vineyard is Israel and Judah. The song of Isaiah 5 described how God carefully cultivated Israel before intentionally allowing it to be destroyed. This was due to Israel's injustice against the poor and powerless, as well as the outcry against His people's unrighteousness.Now, Isaiah speaks about a time when all things will have been made right. This is set during the Lord's reign as king over Israel and the world. The song is of a vineyard restored. Since the Lord identifies Himself in the first person, the implication is that He is the singer of the song. He celebrates His vineyard Israel.
In the first song, the Lord commanded the clouds not to rain on the vineyard (Isaiah 5:6). Now He declares that He waters the vineyard every moment. All the necessary water is supplied by Him at the perfect time. In the first song, the Lord intentionally removed protection so animal invaders could eat and trample the grapes (Isaiah 5:5). Now the Lord says that He protects the vineyard night and day to keep anyone from harming or punishing it.
What has changed? During the Messiah's reign on earth, Israel will not worship other gods or practice injustice against the poor. The Lord will be with His people and will restore them. They will be faithful to Him and receive His blessings with gratitude.