David, having in the foregoing verse reflected upon his covenants with
God, here reflects upon his prayers to God, and renews his petition.
Observe, 1. What he prayed for. Having taken God for his portion, he
entreated his favour, as one that knew he had forfeited it, was
unworthy of it, and yet undone without it, but for ever happy if he
could obtain it. We cannot demand God's favour as a debt, but must be
humble suppliants for it, that God will not only be reconciled to us,
but accept us and smile upon us. He prays, "Be merciful to me, in the
forgiveness of what I have done amiss, and in giving me grace to do
better for the future." 2. How he prayed--with his whole heart, as one
that knew how to value the blessing he prayed for. The gracious soul is
entirely set upon the favour of God, and is therefore importunate for
it. I will not let thee go except thou bless me. 3. What he
pleaded--the promise of God: "Be merciful to me, according to thy word.
I desire the mercy promised, and depend upon the promise for it." Those
that are governed by the precepts of the word and are resolved to keep
them (v. 57) may plead the promises of the word and take the comfort of
them.