It shall not be pruned nor digged: vine-dressers use to dig up and open the earth about the roots of the vines, for divers good purposes. The meaning is. I will remove my ministers, who used great care and diligence to make you fruitful. There shall come briers and thorns; I will give you up to your own wicked lusts. I will also command the clouds that they rain no rain on it; I will deprive you of all my blessings, which are oft compared to rain, &c.
Related Commentaries of Isaiah 5:6
Isaiah 5:6
6 And I will lay it waste: it shall not be pruned, nor digged; but there shall come up briers and thorns: I will also command the clouds that they rain no rain upon it.