Charles H. Spurgeon on Psalms 129:1

They. In speaking of the enemies of Israel simply by the pronoun "they", without being more specific, the Psalmist aggravates the greatness of the evil more than if he had expressly named the Assyrians or the Egyptians. By not specifying any particular class of foes, he tacitly intimates that the world is filled with innumerable bands of enemies, whom Satan easily arms for the destruction of good men, his object being that new wars may arise continually on every side. History certainly bears ample testimony that the people of God had not to deal with a few enemies, but that they were assaulted by almost the whole world; and further, that they were molested not only by external foes, but also by those of an internal kind, by such as professed to belong to the Church. —John Calvin.