John Gill Bible Commentary

Lest mine enemy say, I have prevailed against him,.... Which is an argument God takes notice of; and for which reason he does not give up his people into the hands of their enemies; see Deu 32:27. The Chaldee paraphrase interprets this of the evil imagination or corruption of nature, and represents it as a person, as the Apostle Paul does in Rom 7:15; and which may be said to prevail, when it pushes on to sin, and hinders doing good, and carries captive; and it may be applied to Satan, the great enemy of God's people, who triumphs over them, when he succeeds in his temptations; and those that trouble me rejoice when I am moved; meaning from his house and family, from his country and kingdom, from a prosperous state and condition to a distressed one; at which the troublers of David's peace would rejoice. They that trouble the saints are sin, Satan, and the world; and the two last rejoice when they are in an uncomfortable and afflicted condition; and especially Satan rejoices when he gains his point, if it is but to move them from any degree of steadfastness, of faith and hope, or from the ways of God in any respect: the Targum adds, "from thy ways"; for to be moved so as to perish eternally they cannot, being built upon the Rock of ages, and surrounded by the power and grace of God.