The parable of the vineyard reaches its breaking point. After loving care yields only bitter disappointment, the owner decides to completely abandon the property and actively destroy it. God makes a firm decision to turn the area into a permanent wasteland [מלבי״ם]. It will become an empty space of wild growth, completely unfit for future building or farming [רש״י, שד״ל, מלבי״ם, רד״ק]. The abandonment begins with the end of all agricultural care. There will be no more pruning to strengthen the vines and increase their fruit, nor will there be any hoeing to clear away the surrounding weeds [רד״ק, מצודת דוד, אבן עזרא]. As a result of this neglect, the land will be overrun. The primary approach among commentators is that the ground will be covered in wild thorns and weeds that naturally take over an unworked field. However, an alternative perspective suggests a more active destruction, where strong, stone-splitting worms emerge from the absolute ruin [רש״י].
The turning point of the story occurs when the owner commands the clouds to hold back their rain. Since controlling the weather is impossible for an ordinary person, this command makes it absolutely clear that the owner of the vineyard is God Himself [שד״ל, ביאור שטיינזלץ]. Beneath the surface of the story, the destruction of the vineyard represents the removal of God's protection and guidance from the Israelites. The end of the farming work symbolizes the loss of national leadership, royalty, and Torah instruction [מלבי״ם, אברבנאל]. The overgrowth of thorns reflects the growing power of the wicked [אבן עזרא]. It can also represent the Israelites' own bad actions becoming a curse [רד״ק], or foreign nations being brought into the Land of Israel to take the place of the exiled Ten Tribes [אברבנאל].
The command to stop the rain carries two main meanings. On a physical level, it is a literal punishment where God holds back rainfall, removing physical blessing from the land [רד״ק, אברבנאל, מלבי״ם]. On a deeper, symbolic level accepted by many commentators, the clouds represent the prophets. In this view, God will take away the spirit of prophecy and stop sending prophets to correct and guide the Israelites, leaving the nation in complete spiritual ruin [אבן עזרא, מלבי״ם, רד״ק, אברבנאל].