John Calvin on 1 Peter 3:4

4 But let it be the hidden, man of the heart The contrast here ought to be carefully observed. Cato said, that they who are anxiously engaged in adorning the body, neglect the adorning of the mind: so Peter, in order to restrain this desire in women, introduces a remedy, that they are to devote themselves to the cultivation of their minds. The word heart, no doubt means the whole soul. He at the same time shews in what consists the spiritual adorning of women, even in the incorruptness of a meek and quiet spirit “Incorruptness,” as I think, is set in opposition to things which fade and vanish away, things which serve to adorn the body. Therefore the version of Erasmus departs from the real meaning. In short, Peter means that the ornament of the soul is not like a fading flower, nor consists in vanishing splendor, but is incorruptible. By mentioning quiet and a tranquil spirit, he marks out what especially belongs to women; for nothing becomes them more than a placid and a sedate temper of mind. The best construction is to regard “adorning,” or ornament, as understood after “incorruptible:”

“But the hidden man of the heart, clothed in (or with) the incorruptible adorning of a mild and quiet spirit.”

“Mild” or meek, not given to passion or wrath, patient, not proud nor arrogant; quiet, peaceable, not garrulous, not turbulent, nor given to strife and contention. — Ed. For we know how outrageous a being is an imperious and a self-willed woman. And further, nothing is more fitted to correct the vanity of which Peter speaks than a placid quietness of spirit.

What follows, that it is in the sight of God of great price, may be referred to the whole previous sentence as well as to the word spirit; the meaning indeed will remain the same. For why do women take so much care to adorn themselves, except that they may turn the eyes of men on themselves? But Peter, on the contrary, bids them to be more anxious for what is before God of a great price.

1 Peter 3:5-6

5. For after this manner in the old time the holy women also, who trusted in God, adorned themselves, being in subjection unto their own husbands:

5. Sic enim aliquando et sanctae mulieres quae sperabant in Deum, ornabant seipsas, subjectae propriis maritis:

6. Even as Sara obeyed Abraham, calling him lord: whose daughters ye are, as long as ye do well, and are not afraid with any amazement.

6. Quemadmodum et Sara obediebat Abrahae, dominum ipsum appellans, cujus filiae estis factae, si benefeceritis, et non terreamini ullo pavore.