Ellicott's Commentary On The Whole Bible
Psalms 51 - Introduction
LI.
This psalm has been so identified with David, that to surrender the tradition which ascribes it to him seems a literary crime. Indeed, the character of the man has been react so constantly through the medium of Psalms 32, 51, that we must admit that a personality, dear to all the religious world, recedes and becomes less distinct before the criticism which questions the genuineness of the Davidic authorship of either of them. Yet in the case before us we must either break this long cherished association, or admit the last two verses of the psalm to be a later addition for liturgical use.
But the question of authorship does not affect the estimation in which this psalm has always been held, and always will be held, in the Church, as the noblest expression of penitence. Even if it was not originally, directly, and exclusively the expression of an individual’s repentance, but rather the voice of the people of Israel deploring, during the exile, its ancient errors and sins (the only conclusion which completely explains Psalms 51:4, see Note), and praying for a new lease of covenant-favour, yet the associations of the psalm with individual experience of sin and repentance from it are now far too close to be broken, and it must ever remain in the truest sense one of the penitential psalms, suited for private use as well as for that of the Church. It presents as has been rightly said, the Hebrew and Christian idea of repentance; not remorse, not mere general confession of human depravity, not minute confessions of minute sins dragged to light by a too impulsive casuistry, but change of life and mind; and, in the words of Carlyle, “all earnest souls will ever discern in it the faithful struggle of an earnest human soul towards what is good and best.” The parallelism is distinct and well sustained.
Title. — See title Psalms 4.