John Calvin Commentary Psalms 54:1

"Save me, O God, by thy name, And judge me in thy might." — Psalms 54:1 (ASV)

Save me, O God! As David was at this time placed beyond the reach of human assistance, he must be understood as praying to be saved by the name and the power of God, in an emphatic sense, or by these as distinct from the usual means of deliverance.

Though all help must ultimately come from God, there are ordinary methods by which He generally extends it. When these fail, and every earthly support is removed, He must then take the work into His own hands. It was in such a situation that David here fled to the saints’ last asylum and sought to be saved by a miracle of divine power. By appealing, in the second part of the verse, to God as his judge, he asserts his uprightness.

And it must strike us all that, in asking for divine protection, it is an indispensable prerequisite that we be convinced of the goodness of our cause, as it would demonstrate the greatest profanity for anyone to expect that God should patronize iniquity. David was encouraged to pray for deliverance by the goodness of his cause and his consciousness of integrity; nor did he entertain a single doubt that, on presenting this to God, He would act as his defender and punish the cruelty and treachery of his enemies.