Psalm 103:3

Who forgiveth all thine iniquities
The psalmist explains here what he means by benefits, and gives a particular enumeration of them; and begins with the blessing of pardon, which is a special and peculiar benefit; it is according to the riches of divine grace, and the multitude of tender mercies; without which all outward blessings signify nothing; and, without a sense of this, a man is not in a suitable and proper frame to bless the Lord; and this being the first benefit a soul sensible of sin, its guilt and is concerned for, and seeks after; so enjoying it, it is the first he is thankful for: this is rightly ascribed to God; for none can forgive sins but he; and what he forgives are not mere infirmities, peccadillos, the lesser sins of life; but "iniquities", grosser sins, unrighteousnesses, impieties, the most enormous crimes, sins of a crimson and scarlet die; yea, "all" of them, though they are many, more than the hairs of a man's head; he abundantly pardons, multiplies pardons, as sins are multiplied, and leaves none unforgiven; original sin, actual sins, sins of heart, lip, and life, of omission and commission, all are forgiven for Christ's sake: and the special mercy is when a man has an application of this to himself, and can say to his soul, as David to his, God has forgiven "thine" iniquities; for though it may be observed with pleasure, and it is an encouragement to hope in the Lord, that he is a forgiving God, and has forgiven others, yet what would this avail a man, if his sins should not be forgiven? the sweetness of the blessing lies in its being brought home to a man's own soul: and it may be further observed, that this is a continued act; it is not said who has forgiven, and will forgive, though both are true; but "forgiveth", continues to forgive; for as there is a continual virtue in the sacrifice of the Lamb of God to take away the sin of the world, and in his blood to cleanse from all sin, so there is a continual flow of pardoning grace in the heart of God, which is afresh applied to the consciences of his people by his Spirit; and this is a blessing to be thankful for:

who healeth all thy diseases;
not bodily ones, though the Lord is the physician of the bodies as well as of the souls of men, and sometimes heals the diseases of soul and body at once, as in the case of the paralytic man in the Gospel; but spiritual diseases, or soul maladies, are here meant; the same with "iniquities" in the preceding clause: sin is a natural, hereditary, epidemical, nauseous, and mortal disease; and there are many of them, a complication of them, in men, which God only can cure; and he heals them by his word, by means of his Gospel, preaching peace, pardon, and righteousness by Christ; by the blood, wounds, and stripes of his Son; by the application of pardoning grace and mercy; for healing diseases, and forgiving iniquities, are one and the same thing; see ( Isaiah 33:24 ) , and this the Lord does freely, fully, and infallibly, and for which thanks are due unto him; and it would be very ungrateful, and justly resented, should they not be returned to him; see ( Luke 17:15-18 ) .