1 Peter 3:4

But [let it be] the hidden man of the heart
By which is meant internal grace; which gives a beauty and ornament to the soul, far preferable to that which plaiting of the hair, wearing of gold, or any costly apparel, can give to the body: and this is called a man, as it is elsewhere the new man, ( Ephesians 4:24 ) because it has that which answers to what is in man, to his soul, and the powers and faculties of it: this man, or new creature, has a new heart and Spirit; it has a will to that which is spiritually good, and an understanding of divine things, and affections for Christ, for his Gospel, ordinances, ways, and people, and for things above: it has what answers to all the five senses; there is in it a seeing of the Son of God in the glories of his person and the fulness of his grace, and of the invisible things of another world; an hearing of the word, of the voice of Christ, so as to understand it, and live, and to distinguish it from the voice of a stranger; a smelling a sweet savour in the things of God, and of his Spirit, and in the person, blood, righteousness, and sacrifice of Christ; a tasting that the Lord is gracious, his fruits pleasant, and his word sweeter than the honey, or the honeycomb; and a feeling of the burden of sin, an handling of the word of life, a laying hold on Christ, and retaining him: and it has what answers to the parts and members of the body; it has eyes to see with, ears to hear with, hands to receive from Christ, and work with, to his glory, and feet to walk with: it has, in short, all the parts of a man, though these are not yet grown up to perfection; and so that is not yet a perfect man, or arrived to the measure of the stature of the fulness of Christ; but a man it is: and "a man of the heart"; it has its seat there; it is an inward principle in the soul; hence it is called the "inner" and "inward man"; and nothing outward is it, as external humiliation for sin, abstinence from it, reformation of life and manners, a profession of religion, and conformity to Gospel ordinances; but it is something inward, as appears from its names, both here and elsewhere; it is called spirit, seed, the root of the matter, and oil in the vessels; and from the seat and subject of it, the heart, the spirit, the understanding and will, the mind, conscience, and affections: and it is the "hidden man"; it is wisdom in the hidden part; it is hidden from the men of the world; they do not know what it is, nor what it means, nor how it is, or can be; the life of it is hidden from them, and the food it lives upon is hidden manna to them, and so are both its joys and sorrows: it is sometimes hidden from the saints themselves; when they walk in darkness, and see no light, they are at a loss to know whether this principle is in them or not; and it is hidden from other believers, till they give an account of it to them, when by comparing it with the word of God, and their own experience, they perceive it is the grace of God in them; and it is hidden from Satan, it is out of his reach, he cannot touch it; though he can touch the old man, and stir up the corruptions of it, yet he cannot touch the new man, that which is born of God, nor hurt or destroy it; but it is not hidden from God; he sees it where men cannot, being covered with a variety of infirmities and sins, and knows it is not where men sometimes think it is. The nature of this hidden man is further expressed by what follows,

in that which is not corruptible;
it is opposed to corruptible things, as the outward adorning consists of, such as plaited hair, silver and gold, golden chains, rings and costly apparel; nor is it corrupt in itself; the old man is corrupt according to its deceitful lusts, but this new man, the hidden man of the heart, has no corruption in it, nor cleaving to it: it is the workmanship of God, and is created in righteousness and holiness; though it is as yet imperfect, there is nothing impure in it; nor can it ever perish, or be lost; it is an incorruptible seed, and will always remain when gold will perish, and the best of garments be moth eaten, and decay:

[even the ornament] of a meek and quiet spirit;
this is one, and a principal part of the inward adorning, or hidden man of the heart; and those that are possessed of such a spirit are not easily provoked to anger; patiently bear, and put up with injuries; carry themselves affably and courteously unto all; entertain the meanest thoughts of themselves, and the best of others; do not envy the gifts and graces of others, and are willing to be instructed and admonished by the meanest saint; quietly submit to the will of God, in all adverse dispensations of Providence; and ascribe all they have, and are, to the free grace of God, and reckon that when they have done all they can, they are but unprofitable servants. This grace of meekness, humility, and quietness, is a fruit of the Spirit, and so a part of the hidden man, and is what is very ornamental to a believer; it is his clothing, his inward adorning, and what makes him lovely in the sight of God, and of his people; see ( 1 Peter 5:5 ) and it is very useful to him in hearing the word, in giving a reason of the hope that is in him, in restoring others, and in showing forth a good conversation; and particularly it greatly becomes, and exceedingly beautifies women professing godliness; who ought to bear much with their husbands, and be in silence, which is what the apostle has a principal regard unto: and to encourage the more to the exercise of it, adds,

which is in the sight of God of great price;
which may refer to the whole adorning, to the hidden man of the heart, which is incorruptible, in opposition to the outward adorning, which may be esteemed by men, and be precious in their sight; and particularly to the ornament of meekness and quietness of spirit; for God has a great regard to the meek, humble, and quiet souls; he lifts them up, when cast down; he causes glad tidings to be preached to them; he increases their joy in the Lord; he feeds them, when hungry, to their satisfaction; he guides them in judgment, and teaches them his ways; he will rise up in judgment for them, and reprove with equity for their sake; he gives more grace unto them, and beautifies them with salvation, and will cause them to inherit the earth.