5 And because the whole of this passage is the utterance of One in the form of a servant— of a servant obedient unto the death of the Cross— which He took upon Him and for which He supplicates the saving help of the Name that belongs to God, and being sure of salvation by that Name, He immediately adds: and judge Me by Your power. For now as the reward for His humility in emptying Himself and assuming the form of a servant, in the same humility in which He had assumed it, He was asking to resume the form which He shared with God, having saved to bear the Name of God that humanity in which as God He had obediently condescended to be born.
And in order to teach us that the dignity of this Name whereby He prayed to be saved is something more than an empty title, He prays to be judged by the power of God. For a right award is the essential result of judgment, as the Scripture says: Becoming obedient unto death , yea, the death of the Cross. Wherefore also God highly exalted Him and gave unto Him the name which is above every name. Thus, first of all the name which is above every name is given unto Him; then next, this is a judgment of decisive force, because by the power of God, He, Who after being God had died as man, rose again from death as man to be God, as the Apostle says: He was crucified from weakness, yet He lives by the power of God , and again: For I am not ashamed of the Gospel: for it is the power of God unto salvation to every one that believes. For by the power of the Judgment human weakness is rescued to bear God's name and nature; and thus as the reward for His obedience He is exalted by the power of this judgment unto the saving protection of God's name; whence He possesses both the Name and the Power of God. Again, if the Prophet had begun this utterance in the way men generally speak, he would have asked to be judged by mercy or kindness, not by power. But judgment by power was a necessity in the case of One Who being the Son of God was born of a virgin to be Son of Man, and Who now being Son of Man was to have the Name and power of the Son of God restored to Him by the power of judgment.
Source: Homilies on the Psalms (New Advent)