From Fr. Patrick:
[In the Upper Room] our Lord explicitly appealed to our psalm...to show that this hatred and this persecution by the world are a realization of prophecy: "But this happened that the word might be fulfilled which is written in their law, 'They hated Me without a cause'" (v. 7, also 68:4 and 108:4).
These, then, are psalms in which the praying voice is that of Christ Himself, and, by reason of her sharing in the sufferings of Christ, the Church prays these psalms in His Person.
The prayer of Christ here is a battle prayer, for He wages war on the forces of sin, darkness, and destruction: "Let ruin come upon them unawares." ... This is the prayer of Christ doing battle with the forces of sin and death, looking forward to the hour of His victory, when His very body, brought down to the grave, wil rise again in the paschal victory: "And my soul shall be joyful in the Lord; it shall rejoice in His salvation. All my bones shall say, 'Lord, who is like You, delivering the poor from him who is too strong for him.'"