May my heart be blameless toward your decrees. Having a little before desired to be endued with a sound understanding he now prays, in a similar manner, for sincere affection of heart. The understanding and affection, as is well known, are the two principle faculties of the human soul, both of which he clearly shows to be depraved and perverse, when he requests that his understanding may be illuminated, and, at the same time, that his heart may be framed to the obedience of the law. This plainly refutes all that the Papists babble about free will. The propher not only here says that God would help him, because his will was weak; but he testifies, without qualification, that uprightness of heart is a gift of the Holy Spirit. We are, moreover, taught by these words, in what the true keeping of the law consists. A great part of mankind, after having carelessly framed their lives according to the Divine law, by outward obedience, think that they want nothing. But the Holy Spirit here declares that no service is acceptable to God, excep that which proceeds from integrity of heart.
Though I am like a wineskin in the smoke, I do not forget your derees. The obvious design of the Psalmist is to teach us, that, although he had been proved by severe trials, and wounded to the quick, he had yet not been withdrawn from the fear of God. In comparing himself to a wineskin, he intimates that he was, as it were, parched by the continual heat of the adversities. Whence we learn, that that sorrow must have been intense which reduced him to such a state of wretchedness and emaciation, that like a shrivelled bottle he was almost dried up. It, however, appears that he want to point out, not only the severity of his affliction, but also its lingering nature - that he was tormented, as it were, at a slow fire; even as the smoke which proceeds from heat bladders by slow degrees. The prophet experienced a long series of griefs, which might have consumed him a hundred times, and that, by their protracted and lingering nature, had he not been sustained by the word of god. In short, it is a genuine evidence of true godlinss, when, although plunged into the deepest afflictions, we yet cease not to submit ourselves to God.