Psalms 64:7 - Joseph Benson’s Commentary on the Old and New Testaments

But God shall shoot at them Though I can neither search out nor prevent their subtle devices, yet God can, and will certainly do it, for he ordains his arrows against persecutors, Psalms 7:13, and his arrows will hit more surely, and fly more swiftly, and pierce more deeply than theirs do or can. They have many arrows, but they are only words, though bitter, and the curse causeless shall not come: but God has one arrow that will be their destruction; his curse, which is never causeless, and therefore shall come. Suddenly shall they be wounded That is, their wound by it will be a surprise upon them, because they were secure, and not apprehensive of any danger.