John Gill Commentary Psalms 89:40

"Thou hast broken down all his hedges; Thou hast brought his strongholds to ruin." — Psalms 89:40 (ASV)

You have broken down all his hedges
Round about his vine, the church; see (Psalms 80:12) . A famous church was raised at Jerusalem, quickly after the death, resurrection, and ascension of Christ, which seemed to be well filled, fenced, and protected; but on a sudden a violent persecution arose, and the members of it were made havoc of, and the ministers of the word were scattered abroad, and which was the breaking down of the hedges; and what was done to the church was taken by Christ as done to himself, as it is here spoken of him; see (Acts 8:1–4) (9:5) , and this might seem contrary to the word and oath of God, that his seed should endure for ever, and his throne as the days of heaven, (Psalms 89:29Psalms 89:36) , when the first Christian church was used in this manner.

But that providence was overruled, for the spread of the Gospel, and the interest of Christ, in other parts; see (Acts 8:4) (11:19-21) , and so no objection to what is before said:

you have brought his strong holds to ruin ;
the same as before, the church of Christ, which seemed to be so well built and fortified; see (Isaiah 26:1) .