Why hast thou broken down -
7. When a vineyard is planted, it is properly fenced to preserve it from being trodden down, or otherwise injured by beasts, and to protect the fruit from being taken by the unprincipled passenger. So God protected Jerusalem and his temple by his own almighty arm; and none of their enemies could molest them as long as they had that protection. As it was now spoiled, it was a proof that that protection had been withdrawn; therefore the psalmist addresses the Lord with, "Why hast thou broken down her hedges?" Had God continued his protection, Jerusalem would not have been destroyed.
Why hast thou then broken down her hedges? - Why hast thou dealt with thy people as one would with a vineyard who should break down all its enclosures, and leave it open to wild beasts? The word rendered hedges means wall or enclosure. Compare the notes at Isaiah 5:2.
So that all they which pass by the way - All travelers; or, wild beasts. So that there is nothing to prevent their coming up to the vine and plucking the grapes.
Do pluck her - Pluck, or pick off the grapes; or, if the phrase “all which pass by the way” denotes wild beasts, then the meaning is, that they eat off the leaves and branches of the vine.