In these words the Psalmist declares, that in consequence of having obeyed God's commandments he had obtained more wisdom and understanding than those who had first enlightened his ignorance, and were once more enlightened than he. As if he said, 'When I was a child, I was instructed in religious knowledge by kind and pious friends, who told me who my Maker was, what great things He had done for me, how much I owed to Him, and how I was to serve Him. All this I learned from them, and I rejoice that they taught it me: yet they did more; they set me in the way to gain a knowledge of religious truth in another and higher manner. They not only taught me, but trained me; they were careful that I should not only know my duty, but do it. They obliged me to obey; they obliged me to begin a religious course of life, which (praised be God!) I have ever pursued; and this obedience to His commandments has brought me to a clearer knowledge of His truth, than any mere instruction could convey. I have been taught, not from without merely, but from within. I have been taught by means of a purified heart, by a changed will, by chastened reins, by a mortified appetite, by a bridled tongue, by eyes corrected and subdued.